unit_date

A unit base date library for Node.js, Deno and Browser.

Unit

A unit means the smallest unit of date.

Unit	Example
years	2023
months	2023-04
days	2023-04-12
hours	2023-04-12 03
minutes	2023-04-12 13:20
seconds	2023-04-12 13:20:45

If the units lower than unit of the Date objects are different, unit_date treats them as the same even .

functions

`unit()`

let date = new Date('2023-04-10 13:20:45.364')

unit(date, 'years')   // => 2023-01-01 00:00:00.000
unit(date, 'months')  // => 2023-04-01 00:00:00.000
unit(date, 'days')    // => 2023-04-12 00:00:00.000
unit(date, 'hours')   // => 2023-04-12 13:00:00.000
unit(date, 'minutes') // => 2023-04-12 13:20:00.000
unit(date, 'seconds') // => 2023-04-12 13:20:45.000
unit(date)            // => 2023-04-12 13:20:45.364 (clone)

`diff()`

let left = new Date('2023-04-12 13:20:45.364')
let right = new Date('2022-04-12 13:20:45.364')

diff(left, right, 'years')   // => 1
diff(left, right, 'months')  // => 12
diff(left, right, 'days')    // => 365
diff(left, right, 'hours')   // => 8,760 (=365*24)
diff(left, right, 'minutes') // => 525,600 (=365*24*60)
diff(left, right, 'seconds') // => 31,536,000 (=365*24*60*60)
diff(left, right)            // => 31,536,000,000 (=365*24*60*60*1000)

`set()`

let date = new Date('2023-04-10 13:20:45.364')

let value = {
  years: 2010,
  months: 10,
  days: 10,
  hours: 10,
  minutes: 10,
  seconds: 10,
}

set(date, value, 'years')   // => 2010-01-01 00:00:00.000
set(date, value, 'months')  // => 2010-10-01 00:00:00.000
set(date, value, 'days')    // => 2010-10-10 00:00:00.000
set(date, value, 'hours')   // => 2010-10-10 10:00:00.000
set(date, value, 'minutes') // => 2010-10-10 10:10:00.000
set(date, value, 'seconds') // => 2010-10-10 10:10:10.000
set(date, value)            // => 2010-10-10 10:10:10.364

No carry up.

let date = new Date('2023-04-10 13:20:45.364')
set(date, { days: 31 }) // => 2023-04-30 13:20:45.364

`add()`

let date = new Date('2023-04-10 13:20:45.364')

let value = {
  years: 10,
  months: 10,
  days: 10,
  hours: 10,
  minutes: 10,
  seconds: 10,
}

add(date, value, 'years')   // => 2033-01-01 00:00:00.000
add(date, value, 'months')  // => 2034-02-01 00:00:00.000
add(date, value, 'days')    // => 2034-02-20 00:00:00.000
add(date, value, 'hours')   // => 2034-02-20 23:00:00.000
add(date, value, 'minutes') // => 2034-02-20 23:30:00.000
add(date, value, 'seconds') // => 2034-02-20 23:30:55.000
add(date, value)            // => 2034-02-20 23:30:55.364

`next()`

let date = new Date('2023-04-10 13:20:45.364')

next(date, { days: 5 })            // => 2023-05-05 00:00:00.000
next(date, { days: 5, hours: 9 })  // => 2023-05-05 09:00:00.000
next(date, { days: 15 })           // => 2023-04-15 00:00:00.000
next(date, { days: 15 }, 'months') // => 2023-05-15 00:00:00.000

`prev()`

let date = new Date('2023-04-10 13:20:45.364')

prev(date, { days: 15 })           // => 2023-03-15 00:00:00.000
prev(date, { days: 15, hours: 9 }) // => 2023-03-15 09:00:00.000
prev(date, { days: 5 })            // => 2023-04-05 00:00:00.000
prev(date, { days: 5 }, 'months')  // => 2023-03-05 00:00:00.000