# App compilation date

**URL:** https://forum.crystal-lang.org/t/app-compilation-date/3935
**Category:** Help & Support
**Created:** [October 13, 2021, 1:53pm UTC](https://forum.crystal-lang.org/t/app-compilation-date/3935 "2021-10-13T13:53:49Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![hutou](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/hutou/32/1337_2.png) [@hutou](https://forum.crystal-lang.org/u/hutou)
#### Post date: [October 13, 2021, 1:53pm UTC](https://forum.crystal-lang.org/t/app-compilation-date/3935/1 "2021-10-13T13:53:49Z")

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Hi,  
Is there a Crystal constant allowing to display the compilation datetime of a program?  
Thanks ?

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### Author: ![bcardiff](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/bcardiff/32/3_2.png) [@bcardiff](https://forum.crystal-lang.org/u/bcardiff)
#### Post date: [October 13, 2021, 2:25pm UTC](https://forum.crystal-lang.org/t/app-compilation-date/3935/2 "2021-10-13T14:25:32Z")

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In [Use SOURCE\_DATE\_EPOCH only to determine compiler date by straight-shoota · Pull Request #9088 · crystal-lang/crystal · GitHub](https://github.com/crystal-lang/crystal/pull/9088) you can see how we used to do that for the compiler itself, but then why we preferred to use env vars only.