Periodic times making us sad yet resolved (8)
I believe the answer is:
tuesdays
'periodic times' is the definition.
'us sad yet resolved' is the wordplay.
'resolved' indicates anagramming the letters.
'us'+'sad'+'yet'='ussadyet'
'ussadyet' anagrammed gives 'TUESDAYS'.
'making' is the link.
(Other definitions for tuesdays that I've seen before include "Nautical jacket" , "24-hour periods?" , "Weekdays steady us" , "''... child is full of grace'' (7'1)" .)