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myleftshoe
myleftshoe

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Javascript dates in milliseconds

#javascript

I find the js Date object somewhat cumbersome, it's often easier just to work with milliseconds and convert to the required format when presenting to the user. Here's a small lib that does just that! It's simple, flexible, and functional.

https://github.com/myleftshoe/msdate

Examples

Simple 

 import { now, today, days, weeks, years, toDate } from '@mls44/msdate' now 1592692591560 today 1592661600000 fromDate(new Date()) 1592692591566 toDate(today) 2020-06-20T14:00:00.000Z toDate(today + 1 * days) 2020-06-21T14:00:00.000Z toDate(now + 1 * days) 2020-06-21T22:36:31.560Z toDate(today + 4 * weeks) 2020-07-18T14:00:00.000Z toDate(today + 10 * years) 2030-06-21T02:00:00.000Z
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Ranges 

 import { arrayOf, days, today, toDate } from '@mls44/msdate' arrayOf(days, 7).from(today) [ 1592575200000, 1592661600000, 1592748000000, 1592834400000, 1592920800000, 1593007200000, 1593093600000 ] arrayOf(days, 7, toDate).from(today) [ 2020-06-19T14:00:00.000Z, 2020-06-20T14:00:00.000Z, 2020-06-21T14:00:00.000Z, 2020-06-22T14:00:00.000Z, 2020-06-23T14:00:00.000Z, 2020-06-24T14:00:00.000Z, 2020-06-25T14:00:00.000Z ] arrayOf(days, 7, { weekday: 'long' }).from(today) [ 'Saturday', 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday' ] // Or use between: arrayOf(days, { weekday: 'long' }).between(today, today + days * 7) [ 'Saturday', 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday' ]
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In the above examples, you need to import days. Alternatively you can call arrayOf like this:

arrayOf('days', 7) arrayOf({ days: 7})
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Formatting

msdate uses Intl.DateTimeFormat. Provide an options object as per the spec to format.

arrayOf also accepts the same object (or even a function like toDate) as an optional second argument (see above examples).

 import { now, today, toDate, format } from '@mls44/msdate' format(now, toDate) 2020-06-20T23:20:27.448Z format(now, { weekday: 'long' }) Sunday
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Functional

toDate, fromDate, and format can be used functionally, e.g. [...].map(toDate).

 import { now, today, arrayOf, days, toDate, fromDate, format } from '@mls44/msdate' arrayOf(days, 7).from(today).map(toDate) [ 2020-06-20T14:00:00.000Z, 2020-06-21T14:00:00.000Z, 2020-06-22T14:00:00.000Z, 2020-06-23T14:00:00.000Z, 2020-06-24T14:00:00.000Z, 2020-06-25T14:00:00.000Z, 2020-06-26T14:00:00.000Z ] arrayOf(days, 7).from(today).map(format({ weekday: 'long' })) [ 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday' ] [ new Date('2020-06-19T14:00:00.000Z'), new Date('2020-06-20T14:00:00.000Z'), new Date('2020-06-21T14:00:00.000Z'), new Date('2020-06-22T14:00:00.000Z'), new Date('2020-06-23T14:00:00.000Z'), new Date('2020-06-24T14:00:00.000Z'), new Date('2020-06-25T14:00:00.000Z') ].map(fromDate) [ 1592575200000, 1592661600000, 1592748000000, 1592834400000, 1592920800000, 1593007200000, 1593093600000 ]
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It's a small lib that meets a specific requirement rather than a swiss army knife.

That's it, thanks for reading!

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