Is there like a best time during the day to answer or ask a question? In other words, when is there the most amount of users active who can respond and/or upvote your questions and answers?
There is a blogpost by Jeff Atwood on exactly this. In it, he states:
Looks like the most popular time to post is between 15:00 and 22:00 GMT/UTC, at least for all Stack Overflow data between launch and today.
You'll have to convert those GMT hours to your local time zone, of course.
For the USA, that's:
Eastern Standard Time GMT/UTC minus 5 hours
Central Standard Time GMT/UTC minus 6 hours
Mountain Standard Time GMT/UTC minus 7 hours
Pacific Standard Time GMT/UTC minus 8 hours
It is likely that the same times are relevant for BioSE as well, but might differ a bit depending on the specific user base here (e.g. where they are located).
There are also a couple of questions at Meta-SE on this:
What is the best time to ask questions?
When's the best day and best time to post a question to Stackoverflow.com?