Donkey's years (English) — Donkey's ears is rhyming slang, replacing 'ears' with 'years'. 'Donkey's (y)ears' implies a long time because donkey's ears are long, while 'donkey's years' is also supported by the belief that donkeys live a long time.
Donkey's years — Çok uzun bir süre, oldukça uzun bir zaman.
"Donkey's years" in lyrics
never in a couple
Or at least not for very long
Us lot, we sent our chicks packing
donkey's years ago <fn> https://en.wiktionary.org/wiki/donkey%27s_years</fn>
You, you’re still in the lurch
with your one and it’s driving you nuts