When is a good time and day to buy airline tickets? Monday? Tuesday? Wednesday? 1am? 2am?

Weeks in advance, middle of the weekday on non holidays and the earlier the flight the better.

What @sboolay, said and also use the private/incognito search on your phone, the more you exit and leave a site they hike up the prices and by using a private search it’s like you are visiting the site for the first time every time.