CODEWITHSUNDEEP
javascriptreactjsmomentjs
Profer
Profer

Reputation: 643

How to subtract time using moment

I have start and end dates in my component which I am getting using moment library through the time picker.

So suppose my datepicker selects startDate and endDate for the today. Now I need another dates let's say previousStartDate and previousEndDate which should be the same time difference compared to startDate and endDate.

startDate = '20-06-2019 00:00:00'
endDate = '20-06-2019 23:59:59'

So the previousStartDate and previousEndDate should be

previousStartDate = '19-06-2019 00:00:00'
previousEndDate = '19-06-2019 23:59:59'

How can do that?

I have tried this but with no success

  getPreviousStartDates ({ startDate, endDate }) {
     const diff = endDate.diff(startDate)
     const diffDuration = moment.duration(diff)
     const subtractStartDate = startDate.subtract(diff)
     console.log({subtractStartDate})
     return subtractStartDate
  }

Some more clarification

Suppose The time difference between the startDate and endDate is 3 days (17-6-2019 00:00:00 && 19-6-2019 23:59:59) then the time difference between previousStartDate and previousEndDate should be the same but past 3 days. (14-6-2019 00:00:00 && 16-6-2019 23:59:59)

Upvotes: 0

Views: 135

Answers (1)

tmadsen
tmadsen

Reputation: 951

Is it a requirement that it is done using momentjs? I'm not so familiar with momentjs, but you could do it in javascript like this:

let start = new Date("2019-06-20 00:00:00");
let end = new Date("2019-06-20 23:59:59");
let duration = end.getTime() - start.getTime(); // milliseconds

let prevStart = new Date(start.getTime() - duration);
let prevEnd = new Date(prevStart.getTime() + duration);

Upvotes: 1

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