@thi.ng/date
Version:
Datetime types, relative dates, math, iterators, composable formatters, locales
325 lines (324 loc) • 6.93 kB
JavaScript
import { isNumber } from "@thi.ng/checks/is-number";
import { isString } from "@thi.ng/checks/is-string";
import { Z2, Z3, Z4 } from "@thi.ng/strings/pad-left";
import {
DAY,
HOUR,
MINUTE,
SECOND
} from "./api.js";
import { ensureDate, ensureEpoch, isLeapYear } from "./checks.js";
import { defFormat } from "./format.js";
import { LOCALE } from "./i18n.js";
import { __precisionToID } from "./internal/precision.js";
import { dayInYear, daysInMonth, weekInYear } from "./units.js";
const dateTime = (epoch, prec) => new DateTime(epoch, prec);
class DateTime {
t;
s;
m;
h;
d;
M;
y;
constructor(epoch = Date.now(), prec = "t") {
const x = ensureDate(epoch);
const id = __precisionToID(prec);
this.y = x.getUTCFullYear();
this.M = id >= 1 ? x.getUTCMonth() : 0;
this.d = id >= 2 ? x.getUTCDate() : 1;
this.h = id >= 3 ? x.getUTCHours() : 0;
this.m = id >= 4 ? x.getUTCMinutes() : 0;
this.s = id >= 5 ? x.getUTCSeconds() : 0;
this.t = id >= 6 ? x.getUTCMilliseconds() : 0;
}
/**
* Readonly property, returning 1-based quarter
*
* @remarks
* - 1 = Jan - Mar
* - 2 = Apr - Jun
* - 3 = Jul - Sep
* - 4 = Oct - Dec
*/
get q() {
return (this.M / 3 | 0) + 1;
}
/**
* Alias readonly property, same as {@link DateTime.weekInYear}.
*/
get w() {
return this.weekInYear();
}
set(d) {
const $d = ensureDateTime(d);
this.y = $d.y;
this.M = $d.M;
this.d = $d.d;
this.h = $d.h;
this.m = $d.m;
this.s = $d.s;
this.t = $d.t;
return this;
}
copy() {
return new DateTime(this.toISOString());
}
getTime() {
return Date.UTC(this.y, this.M, this.d, this.h, this.m, this.s, this.t);
}
withPrecision(prec) {
return new DateTime(this, prec);
}
setPrecision(prec) {
const precID = __precisionToID(prec);
precID < 6 && (this.t = 0);
precID < 5 && (this.s = 0);
precID < 4 && (this.m = 0);
precID < 3 && (this.h = 0);
precID < 2 && (this.d = 1);
precID < 1 && (this.M = 0);
return this;
}
compare(d) {
return this.getTime() - ensureEpoch(d);
}
/**
* Returns true if this instance is before the given date, i.e. if
* `this.compare(d) < 0`.
*
* @param d -
*/
isBefore(d) {
return this.compare(d) < 0;
}
/**
* Returns true if this instance is before the given date, i.e. if
* `this.compare(d) > 0`.
*
* @param d -
*/
isAfter(d) {
return this.compare(d) > 0;
}
equiv(o) {
return maybeIsDate(o) ? this.compare(o) === 0 : false;
}
eqDelta(d, eps = 0) {
return Math.abs(this.getTime() - ensureDate(d).getTime()) <= eps;
}
daysInMonth() {
return daysInMonth(this.y, this.M);
}
dayInYear() {
return dayInYear(this.y, this.M, this.d);
}
/**
* Returns week number according to ISO8601.
*
* @remarks
* Reference:
* https://en.wikipedia.org/wiki/Week#The_ISO_week_date_system
*
*/
weekInYear() {
return weekInYear(this.y, this.M, this.d);
}
/**
* Leap years are multiple of 4, excludingcentennial years that aren’t
* multiples of 400.
*/
isLeapYear() {
return isLeapYear(this.y);
}
incMillisecond() {
if (++this.t > 999) {
this.t = 0;
this.incSecond();
}
return this.t;
}
decMillisecond() {
if (--this.t < 0) {
this.t = 999;
this.decSecond();
}
return this.t;
}
incSecond() {
if (++this.s > 59) {
this.s = 0;
this.incMinute();
}
return this.s;
}
decSecond() {
if (--this.s < 0) {
this.s = 59;
this.decMinute();
}
return this.s;
}
incMinute() {
if (++this.m > 59) {
this.m = 0;
this.incHour();
}
return this.m;
}
decMinute() {
if (--this.m < 0) {
this.m = 59;
this.decHour();
}
return this.m;
}
incHour() {
if (++this.h > 23) {
this.h = 0;
this.incDay();
}
return this.h;
}
decHour() {
if (--this.h < 0) {
this.h = 23;
this.decDay();
}
return this.h;
}
incDay() {
if (++this.d > this.daysInMonth()) {
this.d = 1;
this.incMonth();
}
return this.d;
}
decDay() {
if (--this.d < 1) {
this.decMonth();
this.d = this.daysInMonth();
}
return this.d;
}
incWeek() {
this.d += 7;
const max = this.daysInMonth();
if (this.d > max) {
this.d -= max;
this.incMonth();
}
return this.weekInYear();
}
decWeek() {
this.d -= 7;
if (this.d < 1) {
this.decMonth();
this.d += this.daysInMonth();
}
return this.weekInYear();
}
incMonth() {
if (++this.M > 11) {
this.M = 0;
++this.y;
}
return this.M;
}
decMonth() {
if (--this.M < 0) {
this.M = 11;
--this.y;
}
return this.M;
}
incQuarter() {
this.M += 3;
if (this.M > 11) {
this.M %= 12;
this.y++;
}
return this.q;
}
decQuarter() {
this.M -= 3;
if (this.M < 0) {
this.M += 12;
this.y--;
}
return this.q;
}
incYear() {
return ++this.y;
}
decYear() {
return --this.y;
}
/**
* Returns a new `DateTime` instance relative to this date, but with given
* period added/subtracted.
*
* @param x -
* @param prec -
*/
add(x, prec) {
if (prec === "w") return this.add(x * 7, "d");
if (prec === "q") return this.add(x * 3, "M");
const res = this.copy();
const precID = __precisionToID(prec);
if (precID >= 2) {
res.set(
res.getTime() + x * [DAY, HOUR, MINUTE, SECOND, 1][precID - 2]
);
} else if (prec === "M") {
const y = x / 12 | 0;
res.y += y;
x -= y * 12;
const m = res.M + x;
m > 11 && res.y++;
m < 0 && res.y--;
res.M = m % 12;
if (res.M < 0) res.M += 12;
res.d = Math.min(res.d, res.daysInMonth());
} else if (prec === "y") {
res.y += x;
}
return res;
}
toDate() {
return new Date(this.toISOString());
}
toJSON() {
return this.toISOString();
}
toString() {
return this.toDate().toUTCString();
}
/**
* Returns formatted version using current {@link LOCALE.dateTime}
* formatter.
*
* @remarks
* The host environment's locale is NOT used. Only the currently active
* `LOCALE` is relevant.
*/
toLocaleString() {
return defFormat(LOCALE.dateTime)(this, true);
}
toISOString() {
return `${Z4(this.y)}-${Z2(this.M + 1)}-${Z2(this.d)}T${Z2(
this.h
)}:${Z2(this.m)}:${Z2(this.s)}.${Z3(this.t)}Z`;
}
valueOf() {
return this.getTime();
}
}
const ensureDateTime = (x, prec = "t") => x instanceof DateTime ? x : new DateTime(x, prec);
const maybeIsDate = (x) => x instanceof DateTime || x instanceof Date || isNumber(x) || isString(x);
export {
DateTime,
dateTime,
ensureDateTime,
maybeIsDate
};