@naturalcycles/js-lib
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Standard library for universal (browser + Node.js) javascript
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text/typescript
import { _assert } from '../error/assert.js'
import type {
IANATimezone,
Inclusiveness,
IsoDate,
IsoDateTime,
IsoMonth,
MutateOptions,
NumberOfHours,
NumberOfMinutes,
SortDirection,
UnixTimestamp,
UnixTimestampMillis,
} from '../types.js'
import type { LocalDate } from './localDate.js'
import { localDate } from './localDate.js'
import { _ms } from './time.util.js'
import { WallTime } from './wallTime.js'
export type LocalTimeUnit = 'year' | 'month' | 'week' | 'day' | 'hour' | 'minute' | 'second'
export enum ISODayOfWeek {
MONDAY = 1,
TUESDAY = 2,
WEDNESDAY = 3,
THURSDAY = 4,
FRIDAY = 5,
SATURDAY = 6,
SUNDAY = 7,
}
export type LocalTimeInput = LocalTime | Date | IsoDate | IsoDateTime | UnixTimestamp
export type LocalTimeInputNullable = LocalTimeInput | null | undefined
export type LocalTimeFormatter = (ld: LocalTime) => string
export type DateTimeObject = DateObject & TimeObject
export type DateTimeObjectInput = DateObject & Partial<TimeObject>
export interface DateObject {
year: number
month: number
day: number
}
export interface TimeObject {
hour: number
minute: number
second: number
}
const weekStartsOn = 1 // mon, as per ISO
const MILLISECONDS_IN_WEEK = 604800000
const SECONDS_IN_DAY = 86400
// const MILLISECONDS_IN_DAY = 86400000
// const MILLISECONDS_IN_MINUTE = 60000
export const VALID_DAYS_OF_WEEK = new Set([1, 2, 3, 4, 5, 6, 7])
/**
* It supports 2 forms:
* 1. 2023-03-03
* 2. 2023-03-03T05:10:02
*/
const DATE_TIME_REGEX_LOOSE = /^(\d{4})-(\d{2})-(\d{2})([Tt\s](\d{2}):?(\d{2})?:?(\d{2})?)?/
/**
* Supports 2 forms:
* 1. 2023-03-03
* 2. 2023-03-03T05:10:02
* Ok, now it allows arbitrary stuff after `:ss`, to allow millis/timezone info,
* but it will not take it into account.
*/
const DATE_TIME_REGEX_STRICT = /^(\d{4})-(\d{2})-(\d{2})[Tt\s](\d{2}):(\d{2}):(\d{2})/
const DATE_REGEX_STRICT = /^(\d\d\d\d)-(\d\d)-(\d\d)$/
export class LocalTime {
constructor(public $date: Date) {}
/**
* Returns [cloned] LocalTime that is based on the same unixtimestamp, but in UTC timezone.
* Opposite of `.local()` method.
*/
toUTC(): LocalTime {
return new LocalTime(new Date(this.$date.toISOString()))
}
/**
* Returns [cloned] LocalTime that is based on the same unixtimestamp, but in local timezone.
* Opposite of `.utc()` method.
*/
toLocal(): LocalTime {
return new LocalTime(new Date(this.$date))
}
/**
* Returns [cloned] fake LocalTime that has yyyy-mm-dd hh:mm:ss in the provided timezone.
* It is a fake LocalTime in a sense that it's timezone is not real.
* See this ("common errors"): https://stackoverflow.com/a/15171030/4919972
* Fake also means that unixTimestamp of that new LocalDate is not the same.
* For that reason we return WallTime, and not a LocalTime.
* WallTime can be pretty-printed as Date-only, Time-only or DateAndTime.
*
* E.g `inTimezone('America/New_York').toISOTime()`
*
* https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
*
* @experimental
*/
inTimezone(tz: IANATimezone): WallTime {
const d = new Date(this.$date.toLocaleString('en-US', { timeZone: tz }))
return new WallTime({
year: d.getFullYear(),
month: d.getMonth() + 1,
day: d.getDate(),
hour: d.getHours(),
minute: d.getMinutes(),
second: d.getSeconds(),
})
}
/**
* UTC offset is the opposite of "timezone offset" - it's the number of minutes to add
* to the local time to get UTC time.
*
* E.g utcOffset for CEST is -120,
* which means that you need to add -120 minutes to the local time to get UTC time.
*
* Instead of -0 it returns 0, for the peace of mind and less weird test/snapshot differences.
*
* If timezone (tz) is specified, e.g `America/New_York`,
* it will return the UTC offset for that timezone.
*
* https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
*/
getUTCOffsetMinutes(tz?: IANATimezone): NumberOfMinutes {
if (tz) {
// based on: https://stackoverflow.com/a/53652131/4919972
const nowTime = this.$date.getTime()
const tzTime = new Date(this.$date.toLocaleString('en-US', { timeZone: tz })).getTime()
return Math.round((tzTime - nowTime) / 60000) || 0
}
return -this.$date.getTimezoneOffset() || 0
}
/**
* Same as getUTCOffsetMinutes, but rounded to hours.
*
* E.g for CEST it is -2.
*
* Instead of -0 it returns 0, for the peace of mind and less weird test/snapshot differences.
*
* If timezone (tz) is specified, e.g `America/New_York`,
* it will return the UTC offset for that timezone.
*/
getUTCOffsetHours(tz?: IANATimezone): NumberOfHours {
return Math.round(this.getUTCOffsetMinutes(tz) / 60)
}
/**
* Returns e.g `-05:00` for New_York winter time.
*/
getUTCOffsetString(tz: IANATimezone): string {
const minutes = this.getUTCOffsetMinutes(tz)
const hours = Math.trunc(minutes / 60)
const sign = hours < 0 ? '-' : '+'
const h = String(Math.abs(hours)).padStart(2, '0')
const m = String(minutes % 60).padStart(2, '0')
return `${sign}${h}:${m}`
}
get(unit: LocalTimeUnit): number {
if (unit === 'year') {
return this.$date.getFullYear()
}
if (unit === 'month') {
return this.$date.getMonth() + 1
}
if (unit === 'day') {
return this.$date.getDate()
}
if (unit === 'hour') {
return this.$date.getHours()
}
if (unit === 'minute') {
return this.$date.getMinutes()
}
if (unit === 'week') {
return getWeek(this.$date)
}
// second
return this.$date.getSeconds()
}
set(unit: LocalTimeUnit, v: number, opt: MutateOptions = {}): LocalTime {
const t = opt.mutate ? this : this.clone()
if (unit === 'year') {
t.$date.setFullYear(v)
} else if (unit === 'month') {
t.$date.setMonth(v - 1)
} else if (unit === 'day') {
t.$date.setDate(v)
} else if (unit === 'hour') {
t.$date.setHours(v)
} else if (unit === 'minute') {
t.$date.setMinutes(v)
} else if (unit === 'second') {
t.$date.setSeconds(v)
} else if (unit === 'week') {
setWeek(t.$date, v, { mutate: true })
}
return t
}
get year(): number {
return this.$date.getFullYear()
}
setYear(v: number): LocalTime {
return this.set('year', v)
}
get month(): number {
return this.$date.getMonth() + 1
}
setMonth(v: number): LocalTime {
return this.set('month', v)
}
get week(): number {
return getWeek(this.$date)
}
setWeek(v: number): LocalTime {
return this.set('week', v)
}
get day(): number {
return this.$date.getDate()
}
setDay(v: number): LocalTime {
return this.set('day', v)
}
get hour(): number {
return this.$date.getHours()
}
setHour(v: number): LocalTime {
return this.set('hour', v)
}
get minute(): number {
return this.$date.getMinutes()
}
setMinute(v: number): LocalTime {
return this.set('minute', v)
}
get second(): number {
return this.$date.getSeconds()
}
setSecond(v: number): LocalTime {
return this.set('second', v)
}
/**
* Based on ISO: 1-7 is Mon-Sun.
*/
get dayOfWeek(): ISODayOfWeek {
return (this.$date.getDay() || 7) as ISODayOfWeek
}
/**
* Returns LocalTime for the given DayOfWeek (e.g Monday), that is in the same week as this.
* It may move the time into the future, or the past, depending on how the desired DayOfWeek is in
* relation to `this`.
*/
setDayOfWeek(dow: ISODayOfWeek): LocalTime {
_assert(VALID_DAYS_OF_WEEK.has(dow), `Invalid dayOfWeek: ${dow}`)
const delta = dow - this.dayOfWeek
return this.plus(delta, 'day')
}
/**
* Returns LocalTime for the given DayOfWeek (e.g Monday), that is in the future,
* in relation to this.
* If this LocalTime is Monday, and desired DoW is also Monday - `this` is returned.
*/
setNextDayOfWeek(dow: ISODayOfWeek): LocalTime {
_assert(VALID_DAYS_OF_WEEK.has(dow), `Invalid dayOfWeek: ${dow}`)
let delta = dow - this.dayOfWeek
if (delta < 0) delta += 7
return this.plus(delta, 'day')
}
setComponents(c: Partial<DateTimeObject>, opt: MutateOptions = {}): LocalTime {
const d = opt.mutate ? this.$date : new Date(this.$date)
// Year, month and day set all-at-once, to avoid 30/31 (and 28/29) mishap
if (c.day || c.month !== undefined || c.year !== undefined) {
d.setFullYear(
c.year ?? d.getFullYear(),
c.month ? c.month - 1 : d.getMonth(),
c.day || d.getDate(),
)
}
if (c.hour !== undefined) {
d.setHours(c.hour)
}
if (c.minute !== undefined) {
d.setMinutes(c.minute)
}
if (c.second !== undefined) {
d.setSeconds(c.second)
}
return opt.mutate ? this : new LocalTime(d)
}
plusSeconds(num: number): LocalTime {
return this.plus(num, 'second')
}
plusMinutes(num: number): LocalTime {
return this.plus(num, 'minute')
}
plusHours(num: number): LocalTime {
return this.plus(num, 'hour')
}
plusDays(num: number): LocalTime {
return this.plus(num, 'day')
}
plusWeeks(num: number): LocalTime {
return this.plus(num, 'week')
}
plusMonths(num: number): LocalTime {
return this.plus(num, 'month')
}
plusYears(num: number): LocalTime {
return this.plus(num, 'year')
}
minusSeconds(num: number): LocalTime {
return this.plus(-num, 'second')
}
minusMinutes(num: number): LocalTime {
return this.plus(-num, 'minute')
}
minusHours(num: number): LocalTime {
return this.plus(-num, 'hour')
}
minusDays(num: number): LocalTime {
return this.plus(-num, 'day')
}
minusWeeks(num: number): LocalTime {
return this.plus(-num, 'week')
}
minusMonths(num: number): LocalTime {
return this.plus(-num, 'month')
}
minusYears(num: number): LocalTime {
return this.plus(-num, 'year')
}
plus(num: number, unit: LocalTimeUnit, opt: MutateOptions = {}): LocalTime {
if (unit === 'week') {
num *= 7
unit = 'day'
}
if (unit === 'year' || unit === 'month') {
const d = addMonths(this.$date, unit === 'month' ? num : num * 12, opt)
return opt.mutate ? this : localTime.fromInput(d)
}
return this.set(unit, this.get(unit) + num, opt)
}
minus(num: number, unit: LocalTimeUnit, opt: MutateOptions = {}): LocalTime {
return this.plus(num * -1, unit, opt)
}
absDiff(other: LocalTimeInput, unit: LocalTimeUnit): number {
return Math.abs(this.diff(other, unit))
}
diff(other: LocalTimeInput, unit: LocalTimeUnit): number {
const date2 = localTime.fromInput(other).$date
const secDiff = (this.$date.valueOf() - date2.valueOf()) / 1000
if (!secDiff) return 0
let r: number
if (unit === 'year') {
r = differenceInMonths(this.$date, date2) / 12
} else if (unit === 'month') {
r = differenceInMonths(this.$date, date2)
} else if (unit === 'day') {
r = secDiff / SECONDS_IN_DAY
} else if (unit === 'week') {
r = secDiff / (7 * 24 * 60 * 60)
} else if (unit === 'hour') {
r = secDiff / 3600
} else if (unit === 'minute') {
r = secDiff / 60
} else {
// unit === 'second'
r = secDiff
}
// `|| 0` is to avoid returning -0
return Math.trunc(r) || 0
}
startOf(unit: LocalTimeUnit, opt: MutateOptions = {}): LocalTime {
if (unit === 'second') return this
const d = opt.mutate ? this.$date : new Date(this.$date)
d.setSeconds(0, 0)
if (unit !== 'minute') {
d.setMinutes(0)
if (unit !== 'hour') {
d.setHours(0)
if (unit !== 'day') {
// year, month or week
if (unit === 'year') {
d.setMonth(0)
d.setDate(1)
} else if (unit === 'month') {
d.setDate(1)
} else {
// week
startOfWeek(d, { mutate: true })
}
}
}
}
return opt.mutate ? this : new LocalTime(d)
}
endOf(unit: LocalTimeUnit, opt: MutateOptions = {}): LocalTime {
if (unit === 'second') return this
const d = opt.mutate ? this.$date : new Date(this.$date)
d.setSeconds(59, 0)
if (unit !== 'minute') {
d.setMinutes(59)
if (unit !== 'hour') {
d.setHours(23)
if (unit !== 'day') {
// year, month or week
if (unit === 'year') {
d.setMonth(11)
}
if (unit === 'week') {
endOfWeek(d, { mutate: true })
} else {
// year or month
const lastDay = localDate.getMonthLength(d.getFullYear(), d.getMonth() + 1)
d.setDate(lastDay)
}
}
}
}
return opt.mutate ? this : new LocalTime(d)
}
/**
* Returns how many days are in the current month.
* E.g 31 for January.
*/
get daysInMonth(): number {
return localDate.getMonthLength(this.$date.getFullYear(), this.$date.getMonth() + 1)
}
isSame(d: LocalTimeInput): boolean {
return this.compare(d) === 0
}
isBefore(d: LocalTimeInput, inclusive = false): boolean {
const r = this.compare(d)
return r === -1 || (r === 0 && inclusive)
}
isSameOrBefore(d: LocalTimeInput): boolean {
return this.compare(d) <= 0
}
isAfter(d: LocalTimeInput, inclusive = false): boolean {
const r = this.compare(d)
return r === 1 || (r === 0 && inclusive)
}
isSameOrAfter(d: LocalTimeInput): boolean {
return this.compare(d) >= 0
}
isBetween(min: LocalTimeInput, max: LocalTimeInput, incl: Inclusiveness): boolean {
let r = this.compare(min)
if (r < 0) return false
r = this.compare(max)
if (r > 0 || (r === 0 && incl[1] === ')')) return false
return true
}
/**
* Checks if this localTime is older (<) than "now" by X units.
*
* Example:
*
* localTime(expirationDate).isOlderThan(5, 'day')
*
* Third argument allows to override "now".
*/
isOlderThan(n: number, unit: LocalTimeUnit, now?: LocalTimeInput): boolean {
return this.isBefore(localTime.fromInput(now ?? new Date()).plus(-n, unit))
}
/**
* Checks if this localTime is same or older (<=) than "now" by X units.
*/
isSameOrOlderThan(n: number, unit: LocalTimeUnit, now?: LocalTimeInput): boolean {
return this.isSameOrBefore(localTime.fromInput(now ?? new Date()).plus(-n, unit))
}
/**
* Checks if this localTime is younger (>) than "now" by X units.
*
* Example:
*
* localTime(expirationDate).isYoungerThan(5, 'day')
*
* Third argument allows to override "now".
*/
isYoungerThan(n: number, unit: LocalTimeUnit, now?: LocalTimeInput): boolean {
return this.isAfter(localTime.fromInput(now ?? new Date()).plus(-n, unit))
}
/**
* Checks if this localTime is same or younger (>=) than "now" by X units.
*/
isSameOrYoungerThan(n: number, unit: LocalTimeUnit, now?: LocalTimeInput): boolean {
return this.isSameOrAfter(localTime.fromInput(now ?? new Date()).plus(-n, unit))
}
getAgeInYears(now?: LocalTimeInput): number {
return this.getAgeIn('year', now)
}
getAgeInMonths(now?: LocalTimeInput): number {
return this.getAgeIn('month', now)
}
getAgeInDays(now?: LocalTimeInput): number {
return this.getAgeIn('day', now)
}
getAgeInHours(now?: LocalTimeInput): number {
return this.getAgeIn('hour', now)
}
getAgeInMinutes(now?: LocalTimeInput): number {
return this.getAgeIn('minute', now)
}
getAgeInSeconds(now?: LocalTimeInput): number {
return this.getAgeIn('second', now)
}
getAgeIn(unit: LocalTimeUnit, now?: LocalTimeInput): number {
return localTime.fromInput(now ?? new Date()).diff(this, unit)
}
isAfterNow(): boolean {
return this.$date.valueOf() > Date.now()
}
isBeforeNow(): boolean {
return this.$date.valueOf() < Date.now()
}
/**
* Returns 1 if this > d
* returns 0 if they are equal
* returns -1 if this < d
*/
compare(d: LocalTimeInput): -1 | 0 | 1 {
const t1 = this.$date.valueOf()
const t2 = localTime.fromInput(d).$date.valueOf()
if (t1 === t2) return 0
return t1 < t2 ? -1 : 1
}
toDateTimeObject(): DateTimeObject {
return {
...this.toDateObject(),
...this.toTimeObject(),
}
}
toDateObject(): DateObject {
return {
year: this.$date.getFullYear(),
month: this.$date.getMonth() + 1,
day: this.$date.getDate(),
}
}
toTimeObject(): TimeObject {
return {
hour: this.$date.getHours(),
minute: this.$date.getMinutes(),
second: this.$date.getSeconds(),
}
}
toFromNowString(now: LocalTimeInput = new Date()): string {
const msDiff = localTime.fromInput(now).$date.valueOf() - this.$date.valueOf()
if (msDiff === 0) return 'now'
if (msDiff >= 0) {
return `${_ms(msDiff)} ago`
}
return `in ${_ms(msDiff * -1)}`
}
toDate(): Date {
return this.$date
}
clone(): LocalTime {
return new LocalTime(new Date(this.$date))
}
get unix(): UnixTimestamp {
return Math.floor(this.$date.valueOf() / 1000) as UnixTimestamp
}
get unixMillis(): UnixTimestampMillis {
return this.$date.valueOf() as UnixTimestampMillis
}
valueOf(): UnixTimestamp {
return Math.floor(this.$date.valueOf() / 1000) as UnixTimestamp
}
toLocalDate(): LocalDate {
return localDate.fromDate(this.$date)
}
/**
* Returns e.g: `1984-06-21 17:56:21`
* or (if seconds=false):
* `1984-06-21 17:56`
*/
toPretty(seconds = true): IsoDateTime {
return (this.toISODate() + ' ' + this.toISOTime(seconds)) as IsoDateTime
// !! Not using toISOString(), as it returns time in UTC, not in local timezone (unexpected!)
// const s = this.$date.toISOString()
// return s.slice(0, 10) + ' ' + s.slice(11, seconds ? 19 : 16)
}
/**
* Returns e.g: `1984-06-21T17:56:21`
*/
toISODateTime(): IsoDateTime {
return (this.toISODate() + 'T' + this.toISOTime()) as IsoDateTime
// !! Not using toISOString(), as it returns time in UTC, not in local timezone (unexpected!)
// return this.$date.toISOString().slice(0, 19)
}
/**
* Returns e.g: `1984-06-21`, only the date part of DateTime
*/
toISODate(): IsoDate {
const { year, month, day } = this.toDateObject()
return [
String(year).padStart(4, '0'),
String(month).padStart(2, '0'),
String(day).padStart(2, '0'),
].join('-') as IsoDate
// !! Not using toISOString(), as it returns time in UTC, not in local timezone (unexpected!)
// return this.$date.toISOString().slice(0, 10)
}
/**
* Returns e.g: `1984-06`
*/
toISOMonth(): IsoMonth {
return this.toISODate().slice(0, 7) as IsoMonth
}
/**
* Returns e.g: `17:03:15` (or `17:03` with seconds=false)
*/
toISOTime(seconds = true): string {
const { hour, minute, second } = this.toTimeObject()
return [
String(hour).padStart(2, '0'),
String(minute).padStart(2, '0'),
seconds && String(second).padStart(2, '0'),
]
.filter(Boolean)
.join(':')
// !! Not using toISOString(), as it returns time in UTC, not in local timezone (unexpected!)
// return this.$date.toISOString().slice(11, seconds ? 19 : 16)
}
toWallTime(): WallTime {
return new WallTime(this.toDateTimeObject())
}
/**
* Returns e.g: `19840621_1705`
*/
toStringCompact(seconds = false): string {
const { year, month, day, hour, minute, second } = this.toDateTimeObject()
return [
String(year).padStart(4, '0'),
String(month).padStart(2, '0'),
String(day).padStart(2, '0'),
'_',
String(hour).padStart(2, '0'),
String(minute).padStart(2, '0'),
seconds ? String(second).padStart(2, '0') : '',
].join('')
}
toString(): IsoDateTime {
return this.toISODateTime()
}
toJSON(): UnixTimestamp {
return this.unix
}
format(fmt: Intl.DateTimeFormat | LocalTimeFormatter): string {
if (fmt instanceof Intl.DateTimeFormat) {
return fmt.format(this.$date)
}
return fmt(this)
}
}
class LocalTimeFactory {
/**
* Creates a LocalTime from the input, unless it's falsy - then returns undefined.
*
* `localTime` function will instead return LocalTime of `now` for falsy input.
*/
orUndefined(input: LocalTimeInputNullable): LocalTime | undefined {
return input || input === 0 ? this.fromInput(input) : undefined
}
/**
* Creates a LocalTime from the input, unless it's falsy - then returns LocalTime.now
*/
orNow(input: LocalTimeInputNullable): LocalTime {
return input || input === 0 ? this.fromInput(input) : this.now()
}
now(): LocalTime {
return new LocalTime(new Date())
}
/**
Convenience function to return current Unix timestamp in seconds.
Like Date.now(), but in seconds.
*/
nowUnix(): UnixTimestamp {
return Math.floor(Date.now() / 1000) as UnixTimestamp
}
/**
Convenience function that retuns the same as Date.now(), but with proper type of UnixTimestampMillis.
*/
nowUnixMillis(): UnixTimestampMillis {
return Date.now() as UnixTimestampMillis
}
/**
* Create LocalTime from LocalTimeInput.
* Input can already be a LocalTime - it is returned as-is in that case.
* Date - will be used as-is.
* String - will be parsed as strict `yyyy-mm-ddThh:mm:ss`.
* Number - will be treated as unix timestamp in seconds.
*/
fromInput(input: LocalTimeInput): LocalTime {
if (input instanceof LocalTime) return input
if (input instanceof Date) {
return this.fromDate(input)
}
if (typeof input === 'number') {
return this.fromUnix(input)
}
// It means it's a string
// Will parse it STRICTLY
return this.fromIsoDateTimeString(input)
}
/**
* Returns true if input is valid to create LocalTime.
*/
isValid(input: LocalTimeInputNullable): boolean {
if (!input) return false
if (input instanceof LocalTime) return true
if (input instanceof Date) return !Number.isNaN(input.getDate())
// We currently don't validate Unixtimestamp input, treat it as always valid
if (typeof input === 'number') return true
return this.isValidString(input)
}
/**
* Returns true if isoString is a valid iso8601 string like `yyyy-mm-ddThh:mm:dd`.
*/
isValidString(isoString: IsoDateTime | IsoDate | undefined | null): boolean {
return !!this.parseStrictlyOrUndefined(isoString)
}
/**
* Tries to convert/parse the input into LocalTime.
* Uses LOOSE parsing.
* If invalid - doesn't throw, but returns undefined instead.
*/
try(input: LocalTimeInputNullable): LocalTime | undefined {
if (input instanceof LocalTime) return input
if (input instanceof Date) {
if (Number.isNaN(input.getDate())) return
return new LocalTime(input)
}
if (typeof input === 'number') {
return this.fromUnix(input)
}
if (!input) return
const date = this.parseLooselyOrUndefined(input)
return date ? new LocalTime(date) : undefined
}
/**
* Performs STRICT parsing.
* Only allows IsoDateTime or IsoDate input, nothing else.
*/
fromIsoDateTimeString(s: IsoDateTime | IsoDate): LocalTime {
const d = this.parseStrictlyOrUndefined(s)
_assert(d, `Cannot parse "${s}" into LocalTime`)
return new LocalTime(d)
}
/**
* Performs LOOSE parsing.
* Tries to coerce imprefect/incorrect string input into IsoDateTimeString.
* Use with caution.
* Allows to input IsoDate, will set h:m:s to zeros.
*/
parse(s: string): LocalTime {
const d = this.parseLooselyOrUndefined(String(s))
_assert(d, `Cannot parse "${s}" into LocalTime`)
return new LocalTime(d)
}
private parseStrictlyOrUndefined(s: string | undefined | null): Date | undefined {
if (!s || typeof (s as any) !== 'string') return
let m = DATE_TIME_REGEX_STRICT.exec(s)
if (!m) {
// DateTime regex didn't match, try just-Date regex
m = DATE_REGEX_STRICT.exec(s)
if (!m) return
}
const o: DateTimeObject = {
year: Number(m[1]),
month: Number(m[2]),
day: Number(m[3]),
hour: Number(m[4]) || 0,
minute: Number(m[5]) || 0,
second: Number(m[6]) || 0,
}
if (!this.isDateTimeObjectValid(o)) return
return this.createDateFromDateTimeObject(o)
}
private parseLooselyOrUndefined(s: string | undefined | null): Date | undefined {
if (!s || typeof (s as any) !== 'string') return
const m = DATE_TIME_REGEX_LOOSE.exec(s)
if (!m) {
if (s.length < 8) return
// Attempt to parse with Date constructor
const d = new Date(s)
return Number.isNaN(d.getDate()) ? undefined : d
}
const o: DateTimeObject = {
year: Number(m[1]),
month: Number(m[2]),
day: Number(m[3]) || 1,
// [4] is skipped due to extra regex parentheses group
hour: Number(m[5]) || 0,
minute: Number(m[6]) || 0,
second: Number(m[7]) || 0,
}
if (!this.isDateTimeObjectValid(o)) return
return this.createDateFromDateTimeObject(o)
}
/**
* Throws on invalid value.
*/
validateDateTimeObject(o: DateTimeObject): void {
_assert(
this.isDateTimeObjectValid(o),
`Cannot construct LocalTime from: ${o.year}-${o.month}-${o.day} ${o.hour}:${o.minute}:${o.second}`,
)
}
isDateTimeObjectValid(o: DateTimeObject): boolean {
return localDate.isDateObjectValid(o) && this.isTimeObjectValid(o)
}
isTimeObjectValid({ hour, minute, second }: TimeObject): boolean {
return hour >= 0 && hour <= 23 && minute >= 0 && minute <= 59 && second >= 0 && second <= 59
}
fromDate(date: Date): LocalTime {
_assert(
!Number.isNaN(date.getDate()),
'localTime.fromDate is called on Date object that is invalid',
)
return new LocalTime(date)
}
fromUnix(ts: UnixTimestamp): LocalTime {
return new LocalTime(new Date(ts * 1000))
}
/**
* Create LocalTime from unixTimestamp in milliseconds (not in seconds).
*/
fromMillis(millis: UnixTimestampMillis): LocalTime {
return new LocalTime(new Date(millis))
}
fromDateTimeObject(o: DateTimeObjectInput): LocalTime {
// todo: validate?
return new LocalTime(this.createDateFromDateTimeObject(o))
}
private createDateFromDateTimeObject(o: DateTimeObjectInput): Date {
return new Date(o.year, o.month - 1, o.day || 1, o.hour || 0, o.minute || 0, o.second || 0)
}
// private assertNotNull(
// lt: LocalTime | null,
// input: LocalTimeInputNullable,
// ): asserts lt is LocalTime {
// _assert(lt !== null, `Cannot parse "${input}" into LocalTime`, {
// input,
// })
// }
/**
* Returns the IANA timezone e.g `Europe/Stockholm`.
* https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
*/
getTimezone(): IANATimezone {
return Intl.DateTimeFormat().resolvedOptions().timeZone as IANATimezone
}
/**
* Returns true if passed IANA timezone is valid/supported.
* E.g `Europe/Stockholm` is valid, but `Europe/Stockholm2` is not.
*
* This implementation is not optimized for performance. If you need frequent validation -
* consider caching the Intl.supportedValuesOf values as Set and reuse that.
*/
isTimezoneValid(tz: string): boolean {
if (tz === 'UTC') return true // we deliberately consider UTC a valid timezone, while it's mostly used in testing
return Intl.supportedValuesOf('timeZone').includes(tz)
}
sort(items: LocalTime[], dir: SortDirection = 'asc', opt: MutateOptions = {}): LocalTime[] {
const mod = dir === 'desc' ? -1 : 1
return (opt.mutate ? items : [...items]).sort((a, b) => {
const v1 = a.$date.valueOf()
const v2 = b.$date.valueOf()
if (v1 === v2) return 0
return (v1 < v2 ? -1 : 1) * mod
})
}
minOrUndefined(items: LocalTimeInputNullable[]): LocalTime | undefined {
let min: LocalTime | undefined
for (const item of items) {
if (!item) continue
const lt = this.fromInput(item)
if (!min || lt.$date.valueOf() < min.$date.valueOf()) {
min = lt
}
}
return min
}
min(items: LocalTimeInputNullable[]): LocalTime {
const min = this.minOrUndefined(items)
_assert(min, 'localTime.min called on empty array')
return min
}
maxOrUndefined(items: LocalTimeInputNullable[]): LocalTime | undefined {
let max: LocalTime | undefined
for (const item of items) {
if (!item) continue
const lt = this.fromInput(item)
if (!max || lt.$date.valueOf() > max.$date.valueOf()) {
max = lt
}
}
return max
}
max(items: LocalTimeInputNullable[]): LocalTime {
const max = this.maxOrUndefined(items)
_assert(max, 'localTime.max called on empty array')
return max
}
}
// based on: https://github.com/date-fns/date-fns/blob/master/src/getISOWeek/index.ts
function getWeek(date: Date): number {
const diff = startOfWeek(date).getTime() - startOfWeekYear(date).getTime()
return Math.round(diff / MILLISECONDS_IN_WEEK) + 1
}
function setWeek(date: Date, week: number, opt: MutateOptions = {}): Date {
const d = opt.mutate ? date : new Date(date)
const diff = getWeek(d) - week
d.setDate(d.getDate() - diff * 7)
return d
}
// based on: https://github.com/date-fns/date-fns/blob/master/src/startOfISOWeekYear/index.ts
function startOfWeekYear(date: Date): Date {
const year = getWeekYear(date)
const fourthOfJanuary = new Date(0)
fourthOfJanuary.setFullYear(year, 0, 4)
fourthOfJanuary.setHours(0, 0, 0, 0)
return startOfWeek(fourthOfJanuary, { mutate: true })
}
// based on: https://github.com/date-fns/date-fns/blob/fd6bb1a0bab143f2da068c05a9c562b9bee1357d/src/getISOWeekYear/index.ts
function getWeekYear(date: Date): number {
const year = date.getFullYear()
const fourthOfJanuaryOfNextYear = new Date(0)
fourthOfJanuaryOfNextYear.setFullYear(year + 1, 0, 4)
fourthOfJanuaryOfNextYear.setHours(0, 0, 0, 0)
const startOfNextYear = startOfWeek(fourthOfJanuaryOfNextYear, { mutate: true })
const fourthOfJanuaryOfThisYear = new Date(0)
fourthOfJanuaryOfThisYear.setFullYear(year, 0, 4)
fourthOfJanuaryOfThisYear.setHours(0, 0, 0, 0)
const startOfThisYear = startOfWeek(fourthOfJanuaryOfThisYear, { mutate: true })
if (date.getTime() >= startOfNextYear.getTime()) {
return year + 1
}
if (date.getTime() >= startOfThisYear.getTime()) {
return year
}
return year - 1
}
// based on: https://github.com/date-fns/date-fns/blob/fd6bb1a0bab143f2da068c05a9c562b9bee1357d/src/startOfWeek/index.ts
function startOfWeek(date: Date, opt: MutateOptions = {}): Date {
const d = opt.mutate ? date : new Date(date)
const day = d.getDay()
const diff = (day < weekStartsOn ? 7 : 0) + day - weekStartsOn
d.setDate(d.getDate() - diff)
d.setHours(0, 0, 0, 0)
return d
}
// based on: https://github.com/date-fns/date-fns/blob/master/src/endOfWeek/index.ts
function endOfWeek(date: Date, opt: MutateOptions = {}): Date {
const d = opt.mutate ? date : new Date(date)
const day = d.getDay()
const diff = (day < weekStartsOn ? -7 : 0) + 6 - (day - weekStartsOn)
d.setDate(d.getDate() + diff)
return d
}
function addMonths(d: Date, num: number, opt: MutateOptions = {}): Date {
if (!opt.mutate) d = new Date(d)
let day = d.getDate()
let month = d.getMonth() + 1 + num
if (day < 29) {
d.setMonth(month - 1)
return d
}
let year = d.getFullYear()
while (month > 12) {
year++
month -= 12
}
while (month < 1) {
year--
month += 12
}
const monthLen = localDate.getMonthLength(year, month)
if (day > monthLen) day = monthLen
d.setFullYear(year, month - 1, day)
return d
}
function differenceInMonths(a: Date, b: Date): number {
if (a.getDate() < b.getDate()) return -differenceInMonths(b, a)
const wholeMonthDiff = (b.getFullYear() - a.getFullYear()) * 12 + (b.getMonth() - a.getMonth())
const anchor = addMonths(a, wholeMonthDiff).getTime()
const sign = b.getTime() - anchor >= 0 ? 1 : -1
const anchor2 = addMonths(a, wholeMonthDiff + sign).getTime()
return -(wholeMonthDiff + ((b.getTime() - anchor) / (anchor2 - anchor)) * sign)
}
interface LocalTimeFn extends LocalTimeFactory {
(d: LocalTimeInput): LocalTime
}
const localTimeFactory = new LocalTimeFactory()
export const localTime = localTimeFactory.fromInput.bind(localTimeFactory) as LocalTimeFn
// The line below is the blackest of black magic I have ever written in 2024.
// And probably 2023 as well.
Object.setPrototypeOf(localTime, localTimeFactory)