Why does Javascript convert time differently?
These are my two codes:
var date1 = new Date('2017-04-23');
var date2 = new Date('April 23, 2017');
console.log(date1);
console.log(date2);
these are the results:
Sat Apr 22 2017 17:00:00 GMT-0700 (PDT)
Sun Apr 23 2017 00:00:00 GMT-0700 (PDT)
why date1
is it displayed as 22nd at 17:00?
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JavaScript Date
parsing behavior is somewhat unreliable. It looks like when you give it an ISO 8601 string like "2017-04-23" it interprets the date as being in your own timezone, but when you give it an arbitrary string it will interpret it as a UTC date.
Since you are in GMT-7 timezone, 22nd at 17:00 - 23rd at 00:00 in UTC, and when you print a date object, it will always print the UTC date, not the localized date.
So, in the end, both dates are set to 23rd at 00:00, but in different time zones. The first is set to 23 April 00:00 UTC-7, and the second is set to 23 April 00:00 UTC.
It may be a good idea to always set the time zone explicitly to avoid this ambiguity.
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