time machine does not notify re backups

yeah I have the same problem too since moving up to Yosemite - hoping my reply here might help flag someone to help us with a fix for this. Not keeping the backup drive connected 24/7, those timely T.Machine 10-day reminders are sorely missed.

See the document OS X Yosemite Core Technologies available in PDF from the Whats new in Yosemite page I think.

It downloads as OSXYosemite_TO_FF1.PDF and includes discussion of changes made to time machine for those who are not connected to their backup drives all the time.

thanks, but appears the pdf only mentions being notified when tmachine's deleting older backups on the drive that's reconnected, not the "10 days since last backup" message we used to get before upgrading to Yosemite.

Its also saving "missed" backups to your hard-drive for later transfer to time machine - so the backup is still occurring - just not to the time machine disk (same for Icloud backups).

As it is baking up the engineers may have decided you do not need a message -- you may want to give feedback to apple (this is not the place - go to apple support - that you till would like the message because .......

If you are using a laptop - consider getting a docking port (if available) for home use - that way you can have all hardware hooked up to the docking port so the time machine drive should load up and backups continue while at home. (docking ports make it easy to hook up printers, drives, full keyboards and an extra monitor to a lap top and keeps the laptop off the desktop so it can get some air).