# Time zone of CMAQ files

**URL:** <https://forum.cmascenter.org/t/time-zone-of-cmaq-files/1037>\
**Category:** CMAQ\
**Created:** [October 11, 2019, 4:52pm UTC](https://forum.cmascenter.org/t/time-zone-of-cmaq-files/1037 "2019-10-11T16:52:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Sadia](https://avatars.discourse-cdn.com/v4/letter/s/ea666f/32.png) [@Sadia](https://forum.cmascenter.org/u/Sadia)\
**Post date:** [October 11, 2019, 4:52pm UTC](https://forum.cmascenter.org/t/time-zone-of-cmaq-files/1037/1 "2019-10-11T16:52:18Z")

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Hi,  
Good afternoon. Does anyone know where/which file I have to look at if I want to check the "Coordinated Universal Time (UTC) " for my CMAQ domain? I am using a 4km by 4km domain covering North Carolina.

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**Author:** ![cjcoats](https://avatars.discourse-cdn.com/v4/letter/c/ac8455/32.png) [@cjcoats](https://forum.cmascenter.org/u/cjcoats)\
**Post date:** [October 13, 2019, 7:43pm UTC](https://forum.cmascenter.org/t/time-zone-of-cmaq-files/1037/2 "2019-10-13T19:43:29Z")

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By convention, all CMAQ data is already in UTC. Some input data to the emissions model SMOKE is in local time, and SMOKE has means to deal with it (a time-zone cross reference file); see the SMOKE documentation. If you are concerned about daylight savings time vs standard time, see I/O API routine `ISDSTIME()` which returns `TRUE` exactly when fed a date&time for which daylight savings time is in effect.