# About the time used for screening

**URL:** <https://discourse.pangeo.io/t/about-the-time-used-for-screening/2610>\
**Category:** ICESat-2\
**Created:** [July 25, 2022, 3:36am UTC](https://discourse.pangeo.io/t/about-the-time-used-for-screening/2610 "2022-07-25T03:36:28Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![zhenjiang\_wu](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.pangeo.io/zhenjiang_wu/32/1750_2.png) [@zhenjiang\_wu](https://discourse.pangeo.io/u/zhenjiang_wu)\
**Post date:** [July 25, 2022, 3:36am UTC](https://discourse.pangeo.io/t/about-the-time-used-for-screening/2610/1 "2022-07-25T03:36:28Z")

</div>

Is the “start\_time” used to filter the data in GMT?

---

<div class="post-metadata">

**Author:** ![JessicaS11](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.pangeo.io/jessicas11/32/229_2.png) [@JessicaS11](https://discourse.pangeo.io/u/JessicaS11)\
**Post date:** [July 29, 2022, 7:16pm UTC](https://discourse.pangeo.io/t/about-the-time-used-for-screening/2610/2 "2022-07-29T19:16:45Z")

</div>

Yes - the dates and times for ICESat-2 data products are in UTC.

The user guides and Algorithm Theoretical Basis Documents (ATBDs) for each product provide some helpful info on units and metadata. For ATL03, this is noted on p8 of the [user guide](https://nsidc.org/data/atl03/versions/5#anchor-2).