If you think you will have to wait for something that actually will never happen, you can use one of these two expressions:

Dan kun je wachten tot Sint Juttemis
 
Litt: You can wait until Saint Juttemis.

St Juttemis (Saint Juttemis) is an unknown saint. So the day of this saint is a non-existing day!

Dan kun je wachten tot je een ons weegt

Litt: You can wait until you weigh only an ounce (which will never happen)

‘Een ons‘ is an oldfashioned Dutch word  for 100 grams. It is still in use in spoken language, for instance in shops: een onsje. But in writing you will only see ‘100 gr‘.