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uxsolutions / bootstrap-datepicker

A datepicker for twitter bootstrap (@twbs)
Apache License 2.0
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UTC conversion error #1874

Open smthpickboy opened 8 years ago

smthpickboy commented 8 years ago

Code from 1.6.0: _utc_to_local: function(utc){ return utc && new Date(utc.getTime() + (utc.getTimezoneOffset()_60000)); }, _local_to_utc: function(local){ return local && new Date(local.getTime() - (local.getTimezoneOffset()_60000)); }

This is simply wrong. For example: var local = new Date(); Gives me: Fri Apr 29 2016 17:41:40 GMT+0800 But, according to _local_to_utc code, new Date(local.getTime() - (local.getTimezoneOffset()*60000)); result in Sat Apr 30 2016 01:41:40 which is wrong. The correct time should be Fri Apr 29 2016 09:41:40 GMT+0800

So, conclusion: _utc_to_local and _local_to_utc should swap their names

If you just convert time back and forth, this won't be a big problem, you can always get back your original local time , since those 2 conversion are mirrored.

But, this can result in a serious problem, regarding

1743

If you set endDate: "0d" option, which means you can only select dates up to today. But dateWithinRange are checked against UTC time, while startDate/endDate are checked against local time. So when you are trying to set initial date of datepicker to today, such as $('#inputDate').datepicker("setDate", new Date()); It just won't work when my local time is after 16:00, because the bugged _local_to_utc will convert UTC date to tomorrow, so it fails the check of dateWithinRange.

smthpickboy commented 8 years ago

Well, there are 2 problems. No.1 is #1743 No.2 is UTC conversion bug.

If only No.2 is fixed, No.1 will still cause "endDate" problem for GMT-0X00 time zones and similarly "startDate" problems for GMT+0X00 time zones.