What are phrases for the a date meaning "never"? [duplicate]

Solution 1:

You could say when the cows come home.

Also stated as until the cows come home:

The phrase is often used to describe activities regarded as futile or unproductive.

See also:

• a cold day in hell

• that'll be the day

• until one is blue in the face.

Here's another source:

for a very long time

You can diet until the cows come home, and you still won't be a size 4.

We could talk about this problem until the cows come home, but it wouldn't solve anything.

Solution 2:

When hell freezes over is one option, refering to the assumption that hell is an eternally hot and burning place.

Solution 3:

When pigs fly is an oldie but goodie.