How to force the locale/language of a specific app?
TypoClock and TypoClock Free both use the system language as one can see on the app features:


  Multilanguage (widget uses your system language to display day name and month name).  


There's no solution for situations like this, as you can only manipulate the application i18n feature if it was developed with such an option.

You can, as mentioned by Izzy on the comments, email the developer and see if this can be a feature a for future release.