for old times' sake

for old times' sake

In honor of old memories. I'm going to be late tonight because I'm meeting up with some of my old co-workers—we're getting a drink for old times' sake.
See also: old, sake
Farlex Dictionary of Idioms.

for ˈold times’ sake

because of pleasant memories of things you did together in the past: I saw John Smith today. I hadn’t seen him for years. We had a drink together for old times’ sake. I lent him the money for old times’ sake.
See also: old, sake
Farlex Partner Idioms Dictionary

for auld lang syne/for old times' sake

In memory of the good old days; for nostalgic reasons. This expression today is invariably associated with the song Robert Burns allegedly took down from an old man’s singing in 1788. Presumably it began its life with an emphasis on remembering “auld acquaintance”—that is, old friends—which appeared about 1670 in a ballad by Francis Semphill and repeated a phrase that was already proverbial. The anglicized version, for old times’ sake, probably dates from the same period. Eric Partridge deemed both to be clichés by the mid-nineteenth century.
See also: auld, lang, old, sake, syne
The Dictionary of Clichés by Christine Ammer
See also:
  • be at a disadvantage
  • at a disadvantage
  • be out of (one's) head
  • address comments or remarks to
  • address (one's) comments to (someone or something)
  • address (one's) remarks to (someone or something)
  • bang on
  • bang/spot on
  • be in it for
  • be more than (something)
References in classic literature
"For old times' sake," he said and, turning, walked rapidly away along the sidewalk.
Winesberg Ohio
14 we will meet there again for old times' sake. Maria Ressa was also once my student.
Flash! it's August!
"Come on baby, one last chance for old times' sake," Pakistan was seen telling IMF at press time.
'Saudi bailout one time thing, didn't mean anything,' Pakistan reassures IMF
They all have a few drinks, relax, remember the glory days and tell some lies about themselves for old times' sake.
The final act
Even though "Auld Lang Syne" directly translates to "old long ago," it means "good old days," "times gone by" or "for old times' sake" when it's sang. 
Song Meaning Of NYE Tune 'Auld Lang Syne'
When Bob spotted what he thought was a similar model, in bits, at a bike rally recently, he snapped it up for old times' sake.
THE LOVE BIKE; Pair buy back Enfield they eloped on in '56
Until that old album comes on again, and then we're all allowed a singalong - just for old times' sake.
THERE are a few things [...]; it's stylish and timeless, and works in any abode
He's taking Woody (Tom Hanks) with him for old times' sake, but the other toys are bound for the attic in a black bin liner.
WATCH IT
Once a year, we all still get together and put mayonnaise in our hair for old times' sake."
CELEB SECRET CELEB SECRET CELEB SECRET CELEB SECRET
Will Geri wear her Union Jack dress for old times' sake? TOWIE: Our favourite guilty pleasure is back on TV screens tonight, and apparently it kicks off with an almighty argument.
HOT SPUDS SOGGY VEG
So when I heard that the firm was opening a restaurant at the same site, I had to pay a visit with the hubby for old times' sake.
FIVE RIVERS, Walsall EATING OUT
HeRe'S one for old times' sake - an '89 Metro 1.1 automatic with just 10,000 miles.
Mighty fall
With the odd expletive thrown in for old times' sake.
Fates versus Heurelho is a one-sided clash; PICK OF THE DAY
Apparently, Salman has grown fond of all of them and wants a get together for old times' sake. What a way to start the New Year!
Friendly Bigg Boss' gala party
Just for old times' sake, do you think he's trying for another Nine-in-a-Row?
Proposal out of the blue..