Counts from time to time ate out, hatless (6)
I believe the answer is:
totals
'counts' is the definition.
(totaling is a kind of counting)
'from time to time ate out hatless' is the wordplay.
'from time to time' means one should take alternating letters (letters removed on a regular basis).
'ate'+'out'+'hatless'='ateouthatless'
The alternating letters of 'ateouthatless' are 'TOTALS'.
(Other definitions for totals that I've seen before include "Aggregations or sums" , "Sums and aggregates" , "Adds up the entire amounts" , "Kills" .)