From Longman Dictionary of Contemporary Englishfor old times’ sakefor old times’ sakeREMEMBERif you do something for old times’ sake, you do it to remind yourself of a happy time in the past → old
Examples from the Corpus
for old times’ sake• A slight drizzle appeared, just for old times' sake.• I just thought it might have been kinda fun, you know, for old times' sake.• Then one day, just for old times' sake, I paid a visit to Winston Street.• This was really just for old times' sake, just for fun.• Or even, for old times' sake, one of the left splinter parties.