week number systems for Gregorian year according to ISO-8601 or starting on sundays, saturdays

• API
  • dayOfYear
  • weekNumber - ISO 8601 week numbers
  • weekNumberSun - week starting on Sundays
  • weekNumberSat - week starting on Saturdays
  • weekNumberYear - ISO 8601 calendar year, week, and day
  • weekNumberYearSun - calendar year, week, and day starting on Sundays
  • weekNumberYearSat - calendar year, week, and day starting on Saturdays
  • weeksPerYear - ISO 8601 calendar weeks in a given year
  • weeksPerYearSun
  • weeksPerYearSat
• Installation
• Tests
• License

Get day of year in Gregorian year

Parameters

• date?: Date; optional: local date

Example

import { dayOfYear } from 'weeknumber'

dayOfYear(new Date(2017, 11, 31, 12))
//> 365
dayOfYear(new Date(2018, 0, 1, 12))
//> 1

Returns Number, number of day in year (1 ... 366)

ISO-8601 week numbering.

New week starts on Mondays. Used by most European countries, most of Asia and Oceania.

1st week contains 4-7 days of the new year.

Parameters

• date?: Date; optional: local date

Example

import { weekNumber } from 'weeknumber'

weekNumber(new Date(2016, 0, 3, 12)) // Sun
//> 53
weekNumber(new Date(2016, 0, 4, 12)) // Mon
//> 1

Returns Number, week number in ISO 8601 format

North American and Islamic system.

New week starts on Sundays. Used in Canada, United States, India, Japan, Taiwan, Hong Kong, Macau, Israel, South Africa, most of Latin America.

1st week contains 1-7 days of the new year

Parameters

• date?: Date; optional: local date

Example

weekNumberSun(new Date(2016, 0, 2, 12)) // Sat
//> 52
weekNumberSun(new Date(2016, 0, 3, 12)) // Sun
//> 1

Returns Number, week number

Middle Eastern system.

New week starts on Saturdays. Used in most of the Middle East.

1st week contains 1-7 days of the new year

Parameters

• date?: Date; optional: local date

Example

weekNumberSat(new Date(2016, 0, 1, 12)) // Fri
//> 52
weekNumberSat(new Date(2016, 0, 2, 12)) // Sat
//> 1

Returns Number, week number

ISO-8601 calendar year, week, and day

New week starts on Mondays. Used by most European countries, most of Asia and Oceania.

1st week contains 4-7 days of the new year.

Parameters

• date?: Date; optional: local date

Example

weekNumberYear(new Date(2008, 11, 29, 12)) // Monday
//> { year: 2009, week: 1, day: 1 }
weekNumberYear(new Date(2010, 0, 3, 12)) // Sunday
//> { year: 2009, week: 53, day: 7 }

Returns Object, {year, week, day} where day 1=Monday ... 7=Sunday

North American and Islamic system calendar year, week, and day

New week starts on Sundays. Used in Canada, United States, India, Japan, Taiwan, Hong Kong, Macau, Israel, South Africa, most of Latin America.

1st week contains 1-7 days of the new year

Parameters

• date?: Date; optional: local date

Example

weekNumberYearSun(new Date(2009, 0, 3, 12)) // Saturday
//> { year: 2008, week: 52, day: 7 }
weekNumberYearSun(new Date(2009, 0, 4, 12)) // Sunday
//> { year: 2009, week: 1, day: 1 }

Returns Object, {year, week, day} where day 1=Sunday ... 7=Saturday

Middle Eastern system calendar year, week, and day

New week starts on Saturdays. Used in most of the Middle East.

1st week contains 1-7 days of the new year

Parameters

• date?: Date; optional: local date

Example

weekNumberYearSat(new Date(2009, 0, 2, 12)) // Friday
//> { year: 2008, week: 52, day: 7 }
weekNumberYearSat(new Date(2009, 0, 3, 12)) // Saturday
//> { year: 2009, week: 1, day: 1 }

Returns Object, {year, week, day} where day 1=Saturday ... 7=Friday

ISO 8601 calendar weeks in a given year

New week starts on mondays. Used by most European countries, most of Asia and Oceania.

Parameters

• year: number;

Returns number weeks in year

North American and islamic system calendar weeks in a given year

New week starts on sundays. Used in Canada, United States, India, Japan, Taiwan, Hong Kong, Macau, Israel, South Africa, most of Latin America.

Parameters

• year: number;

Returns number weeks in year

Middle Eastern system calendar weeks in a given year

New week starts on saturdays. Used in most of the Middle East.

Parameters

• year: number;

Returns number weeks in year

Requires nodejs.

$ npm install weeknumber

npm test

Unlicense https://unlicense.org/