Pleasant time of day for a greeting (4,9)
I believe the answer is:
good afternoon
'a greeting' is the definition.
(good afternoon is a kind of greeting)
'pleasant time of day' is the wordplay.
'pleasant' becomes 'good'.
'time of day' becomes 'afternoon' (I've seen this before).
'good'+'afternoon'='GOOD AFTERNOON'
'for' is the link.
(Other definitions for good afternoon that I've seen before include "PM greeting" , "Words of salutation" .)