Back In Time - Daily schedule

[ZenPath]

Have just done an upgrade in place from LM18.3 to 19 - flawless: thank you to all involved in keeping this distro so tip top!

I've been exploring back up utilities (had to use timeshift for the upgrade) and have now settled on Back-in-Time: does what I need, so all cool.

I have BiT scheduled for daily back ups using checksum for 01:00. When I close the BiT window (using the 'x' in the top right corner), the application closes completely.

So, my first question is for a scheduled back up, does the system 'wake' the BiT up so that it can do the back up or do I need to leave it running in the background all of the time?

I have the back ups stored on an external 2Tb Seagate USB drive formatted to ext4. My second question is, do I need to leave that drive mounted all of the time (which gives me an icon on my desktop) or it is possible to unmount it so it is still accessible to the system but no longer appears on my desktop?

Thanks for any informed steers on these queries.