In this file:
required strings are:
__('1 month ago', 'social')
__('%s months ago', 'social')
__('1 week ago', 'social')
But in the .pot file we don't have such strings.
Instead we have "1 month" and "ago" separated.
(Similar for other time periods)
As a result - the translation of these strings in not working on the front-end.