需要将UTC时间转换为设备的当前时区

Question

Im using this repo

https://github.com/remirobert/Tempo

Can someone help me understand how to grab the current time zone of the device, and then notify tempo? I am using the timeAgoNow() function of tempo to find display how long ago the post was made, but the timezone difference is messing it up. My datasource is using UTC time.

Answer 1

Cocoa uses UTC internally. for all of its date/time calculations.

If you create an NSDate for now:

NSDate()

You get a date that is the number of elapsed seconds since midnight, 1970 in UTC time.

Dates only have time zones when you display them.

By default logging a date to the console logs it in UTC, which can be confusing.

If I'm working on a project that does a lot of date/time calculations I'll create a debugging method that converts an NSDate to a date/time string in the current locale, which is easier to read/debug without having to mentally convert from UTC back to local time.

I have never used Tempo, so I don't know if it is using date strings, NSDate, or "internet dates" (which are also in UTC, but use a different "zero date" or "epoch date")