As stated in this post: https://www.tibiaqa.com/14089/how-much-time-do-i-need-to-regenerate-my-stamina-from-zero-to-full?show=14089#q14089
You need 20h10 to fully regenerate from 40:00 to 42:00 of stamina. This means you can be 4 hours online every day, and as long as don't go below 40:00, on next day you will have 42:00.
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But, if some of your online time is inside resting zones, you will recover some stamina back even while being online, making it possible to go below 40:00 stamina and be more than 4 hours online.
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My recommendation would be to do like 1:30 hunting every day, leaving 30 min of stamina to be "wasted" at bosses, etc.. (each boss will consume 2 minutes of stamina, if you don't kill anything else). This way you will have a decently long hunt, will be able to kill like 10 bosses and will still have full stamina on next day.