itch.io

I looked more closely into how Ren'Py handles the FileTime time stamps - try changing the get_timestamp function in the backend as follows:

def get_timestamp(self, format=_("%b %d, %Y @ %I:%M %p{#achievement_timestamp}")):
    """
    Return the timestamp when this achievement was granted,
    using the provided string format.
    """
    if self.has():
        format = renpy.translation.translate_string(format)
        return _strftime(format, self._timestamp)
    else:
        return ""

And let me know if that works!