Plugins - dayjs

Day.js has a plugin system to extend functionality. The core is intentionally minimal; plugins add features on demand.

Loading a Plugin

import pluginName from 'dayjs/plugin/pluginName';
dayjs.extend(pluginName);

Official Plugins

Plugin	Description
AdvancedFormat	Extended format tokens like `Q`, `Do`, `k`, `kk`
ArraySupport	Create Day.js from `[year, month, day]` arrays
BadMutable	Makes Day.js mutable (mutates original)
BigIntSupport	BigInt timestamp parsing
BuddhistEra	Buddhist Era (BE) year display
Calendar	`.calendar()` method for calendar-time strings
CustomParseFormat	Parse strings with custom format patterns
DayOfYear	`.dayOfYear()` getter/setter
Duration	Full duration/interval API
IsBetween	`.isBetween()` comparison
IsLeapYear	`.isLeapYear()` check
IsSameOrAfter	`.isSameOrAfter()` comparison
IsSameOrBefore	`.isSameOrBefore()` comparison
IsToday	`.isToday()` check
IsTomorrow	`.isTomorrow()` check
IsYesterday	`.isYesterday()` check
IsoWeek	ISO week getters/setters
IsoWeeksInYear	`.isoWeeksInYear()` method
LocaleData	Access locale-specific data
LocalizedFormat	Locale-aware format tokens (`L`, `LL`, `LT`)
MinMax	`dayjs.max()` and `dayjs.min()`
ObjectSupport	Create Day.js from plain objects
PluralGetSet	Plural getter/setter aliases (`.years()`, `.months()`)
PreParsePostFormat	Hook into parse/format stages
QuarterOfYear	`.quarter()` getter/setter
RelativeTime	`.fromNow()`, `.from()`, `.toNow()`, `.to()`
Timezone	Full timezone support via `dayjs.tz()`
ToArray	`.toArray()` method
ToObject	`.toObject()` method
UpdateLocale	Update locale data at runtime
UTC	UTC mode (`.utc()`, `.local()`, `.utcOffset()`)
WeekOfYear	`.week()` getter/setter
WeekYear	`.weekYear()` getter/setter
Weekday	Locale-aware `.weekday()`

Duration Plugin

dayjs.extend(Duration);

const dur = dayjs.duration(3600000); // 1 hour in ms
dur.humanize(); // "an hour"
dur.format('HH:mm:ss'); // "01:00:00"
dur.minutes(); // 60
dur.as('hours'); // 1

// From an object
const dur2 = dayjs.duration({ hours: 2, minutes: 30 });
dur2.humanize(); // "2.5 hours"

Timezone Plugin

dayjs.extend(UTC);
dayjs.extend(Timezone);

// Guess user timezone
dayjs.tz.guess(); // "Europe/Istanbul"

// Parse in a specific timezone
dayjs.tz('2024-06-15 10:00', 'America/New_York');

// Convert to timezone
dayjs('2024-06-15').tz('Asia/Tokyo');

// Set default timezone
dayjs.tz.setDefault('America/New_York');