Sainsbury's Date

Basic functions to convert a date object or string into Sainsbury's financial calendar components or vice-versa.

Usage

Run npm install sainsburys-date to install the package into your application, then use import (or require) to bring it in.

import sainsburysDate from 'sainsburys-date'

fromDate(date | dateStr)

This converts a Date object or yyyy-mm-dd string into it's Sainsbury's calendar parts.

const date = sainsburysDate.fromDate('2015-10-05')

console.log(date.year) // 2015
console.log(date.quarter) // 3
console.log(date.period) // 8
console.log(date.week) // 2

toDate({ year, quarter, period, week, day })

This calculates the date represented by the passed Sainsbury's calendar parts. Dates are calculated starting from the year option, offset by the quarter, period, week and day optional parts (summated in their respective order).

const a = sainsburysDate.toDate({ year: 2015, period: 8, week: 2 })
const b = sainsburysDate.toDate({ year: 2015, week: 30 })
const c = sainsburysDate.toDate({ year: 2017, day: 15 })
const d = sainsburysDate.toDate({ year: 2017, quarter: 4 })

console.log(a) // new Date('2015-10-04')
console.log(b) // new Date('2015-10-04')
console.log(c) // new Date('2017-03-26')
console.log(d) // new Date('2017-12-17')

Sainsbury's Leap Week / Period?

At some point Sainsbury's will need to introduce a "leap" week or period otherwise the start of the financial year will fall into the previous year!

However, a decision on how to introduce this hasn't been made yet and this won't be a problem until Sun Dec 31 2073 (which will otherwise be the Q1 for 2074)