datenum to UTC?

9 次查看（过去 30 天）
MrKoberec
MrKoberec 2018-10-25
评论： Peter Perkins 2018-10-31
Hi, I have
10-Oct-2013 15:59:00
and I need UTC time
1381435140
Is there any easy way? (time zone GTM-4)
Thanks!
  1 个评论
Guillaume
Guillaume 2018-10-25
That's not UTC time, that's a Unix Time Stamp
It also appears that your input is a datetime not a datenum.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

James Tursa
James Tursa 2018-10-25
编辑：James Tursa 2018-10-25
Are you just looking for how to convert from the former to the latter? E.g.,
s = '10-Oct-2013 15:59:00';
unix_m4 = (datenum(s) - datenum('01-Jan-1970'))*86400 + 4*3600;
or
unix_m4 = seconds((datetime(s) - datetime('01-Jan-1970')) + seconds(4*3600));
or
unix_m4 = seconds(datetime(s,'timezone','-4') - datetime('01-Jan-1970','timezone','UTC'));
This result isn't called UTC btw, it is called Unix time:
https://en.wikipedia.org/wiki/Unix_time
  1 个评论
MrKoberec
MrKoberec 2018-10-26
Thank you, James. Your first suggestion did the job (thank you for including the timezone). I'm using an old version of Matlab (long story) and it does not know the datetime. Sorry I forgot to mention this. Thank you also for the link. I understand it better now.

请先登录，再进行评论。

更多回答（1 个）

jonas
jonas 2018-10-25
编辑：jonas 2018-10-25
Yes, use datetime instead of datenum.
t = datetime('10-Oct-2013 15:59:00','timezone','-04:00')
t_unix = posixtime(t)
  1 个评论
Peter Perkins
Peter Perkins 2018-10-31
'-04:00' is a valid time zone, but perhaps a little dangerous. It's a time zone that does not observe4 DST. If the OP is in, say, Boston, then that would give the wrong answer for 10-Nov. Something like 'America/New_York' is probably the right choice.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Dates and Time 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by