until the cows come home字面意思奶牛回家，引申为无期限地、长久地、很长时间。

【例句】
You can initiate policies until the cows come home, but unless they're monitored at a senior level, you won't get results.
你可以花很长时间来制定政策，但除非高层对之进行监管，否则不会有效果。

This wine's delicious! I could drink it until the cows come home.
这酒很好喝。我可以没完没了地喝下去。