Add / Subtract

The add() method adds a value to an esday object.

The subtract() method subtracts a value from an esday object.

Usage

Method signatures

esday().add(value: number, unit: UnitTypeAddSub): EsDay

esday().subtract(value: number, unit: UnitTypeAddSub): EsDay

parameter	type	description
value	number	number of units to add / subtract
unit	UnitTypeAddSub	unit for add / subtract

Available Units in UnitTypeAddSub

Singular	Plural	Shorthand
year	years	y
quarter	quarters	Q
month	months	M
week	weeks	w
day	days	d
hour	hours	h
minute	minutes	m
second	seconds	s
millisecond	milliseconds	ms

The unit quarter (in short, long and plural forms) requires the plugin QuarterOfYear to be loaded.

Adding multiple values in one step requires the plugin ObjectSupport.

Examples

add

import { esday } from 'esday'

esday('2025-07-17T03:24:46.234').add(2, 'M')
// Returns an instance of EsDay for '2025-09-17T03:24:46.234'

esday('2024-01-31T13:24:35.789').add(1, 'day')
// Returns an instance of EsDay for '2024-02-01T13:24:35.789'

esday('2024-01-31T13:24:35.789').add(15, 'seconds')
// Returns an instance of EsDay for '2024-01-31T13:24:50.789'

subtract

import { esday } from 'esday'

esday('2025-07-17T03:24:46.234').subtract(2, 'M')
// Returns an instance of EsDay for '2025-05-17T03:24:46.234'

esday('2024-01-31T13:24:35.789').subtract(1, 'day')
// Returns an instance of EsDay for '2024-01-30T13:24:35.789'

esday('2024-01-31T13:24:35.789').subtract(15, 'seconds')
// Returns an instance of EsDay for '2024-01-31T13:24:20.789'