Why is January 0 in Javascript date object while year, day, hour, ... starts to 1?

Question

Possible Duplicate:
Zero-based month numbering

Why is January month 0 in JS date object ? For instance, I would expect this snippet to create a date oject for the 8th of Februray 2013. Instead, it's March. All other fields areintuitive. Years are natural as well as day of month and time.

test_date = New Date(2013, 2, 8);

Is there any rational behind this ?

http://stackoverflow.com/questions/1453043/zero-based-month-numbering — Sampson, Jan 09 '13 at 19:16
_"Plus, I had to be done in ten days or something worse than JS would have happened."_ - Brendan Eich — Alex Wayne, Jan 09 '13 at 19:17

score 8 · Accepted Answer · answered Jan 09 '13 at 19:16

8

Because then you can have:

var monthnames = ["Jan","Feb","Mar"....];

And access the array by:

monthnames[myDate.getMonths()]

Similarly for weekdays, where Sunday is 0.

However, years, and days are just numeric values, not indices to some greater meaning.

Side-note: Hours, minutes and seconds are zero-based in "human time" too.

answered Jan 09 '13 at 19:16

Niet the Dark Absol

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Sorry but month is numeric value is well. January is month 1, and December is month 12. Same as day of week. Monday is 1, Tuesday is 2, etc., and Sunday can be either 0 or 7 depending whether Sunday is at the beginning or at the end. – Michael Tsang Feb 27 '19 at 07:57

score 0 · Answer 2 · answered Jan 09 '13 at 19:16

0

There are only 12 months while there can be an infinite number of years. So i would think it is more efficient to use an array of twelve to store the month value.

answered Jan 09 '13 at 19:16

Ibu

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That doesn't address why days start with 1, which is not infinite. – Eric Dec 23 '15 at 20:27

Why is January 0 in Javascript date object while year, day, hour, ... starts to 1?

2 Answers2