Parse Datetime string in local date format in javascript (preferably using luxon)

Question

Suppose I have a datetime string 10/09/2019 10:03:00.000 AM.

Now, if I am in USA, I'll read it as 9th October 2019 and if I am in India, I'll read it as 10th September 2019.

So, my question is how do I parse this string as a Date object in such a way that it is parsed based on the local timezone.

I am using luxon, but, pure javascript solution will also work.

Glandule

What you're describing isn't really related to timezones; it's date format preference based on culture, day/month/year vs month/day/year. If you want that handled properly, you'll likely have to allow your users to set their date format preference, but hopefully for display only. Most systems expect dates/timestamps to be handled in year-month-day hour:minute:second, with or without timezone (+/- offset) included. – Nugatory

Did you read the luxon documentation? moment.github.io/luxon/docs/manual/parsing.html#fromformat – Zischke

fromFormat expects a format to be provided. I want automatic parsing based on culture. I guess as Tim suggested, I need to switch to year-month-day hour:minute:second – Glandule

So your real question is "how do I tell what format the user expects". You can't, so present timestamps in an unambiguous format, and tell the user the format you expect when requesting input. – Friedrick

Answer 1

Using a recent version of Luxon that supports the use of "macro" tokens in the parser:

> DateTime.fromFormat("10/09/2019 10:03:00.000 AM", "D hh:mm:ss.SSS a").toISO()
'2019-10-09T10:03:00.000-04:00'
> DateTime.fromFormat("10/09/2019 10:03:00.000 AM", "D hh:mm:ss.SSS a", { locale: "en-IN" }).toISO()
'2019-09-10T10:03:00.000-04:00'

IMO, this solution is brittle, in the sense that Luxon's parser here very strict, essentially requiring that the date part match exactly DateTime.toFormat in that locale, so differences in 0-padding, slashes vs hyphens, etc.

Airla

I upvoted it, because I found the format of the second argument here – Candlepower

Also note: The 'F' token is great for this format: DateTime.fromFormat("10/09/2019 10:03:00.000 AM", "F"). – Cornucopia