Minecraft Villager Jobs?

I have a quick question, namely: Can villagers change their offers? Because I really want to trade a villager to do repairs. When I finally have one, I have to know whether I have to hurry because it changes it after a while or whether I can take my time.

Actually, they don't change

Villagers only change their truth when they are working on their device. This happens a total of 3 times a day

If you have already traded with the villager, it only changes the prices.

But if you have not yet traded with him, then you can simply dismantle his profession block (Lectern) and place it again, then he should lose his profession and get it again and change the trades in the process.

You have to stop until he can trade mending for you.