Well, there’s http://www.gaiaonline.com.
That’s great, but if you are looking for PURELY Time Management, then just try Diner Dash:http://www.bigfishgames.com/online-games…

You might try popomundo. It’s primarily a “music industry” themed life sim, but you don’t need an ounce of musical talent to play and enjoy it. There are other things you can do besides forming a band and performing shows, and it has an interesting relationship system for interacting with the other players.
It’s played entirely in the browser, so there’s no download.

So you need online time management games? Here they are:
Burger Island – http://www.logler.com/online-games/burge…
Kindergarten – http://www.logler.com/online-games/kinde…
Cake Mania – http://www.logler.com/online-games/cake-…
Cake Mania 2 – http://www.logler.com/online-games/cake-…
Nanny Mania – http://www.logler.com/online-games/nanny…
But if you’ll decide sometime to get downloadable time management game you’ll find bunch of them here: http://www.logler.com/time_management_ga…
Enjoy!