Reply To: Grep duplicate-select first instance

Don’t have an elegant solution for you but this will work, it will remove the second number following the month, tab, number. But it will not remove punctuation following the second date.
There is no real rule to find the months without finding text in other places, so they need to be explicitly defined.

GREP Find and replace
FIND
((January|February|March|April|May|June|July|August|September|October|November|December)\d+)(\d+)

REPLACE
$1

How it works is to find two groups and then only add back the first item found.