Yosi Rosenblum was born in Tel Aviv about 10:30 PM on a date (mm.dd.yyyy) claiming maximal sum of digits.
On what date (mm.dd.yyyy) will he become Bar Mizvah?
(In reply to possible solution
Your final answer is correct, but the begining of a new day in Hebrew (lunar) calendar is at moonrise and not at sunset, 10;30 PM is ok both ways, so my remark is only for protocol.
Yossi will be exactly 13 (Hebrew)yrs old, no extra days.
The date of celebration needs not to be the date of Yossi becoming Bar Mizva (= a grown up person , responsible for his actions).
You can find more by googling hebrew calendar or getting the date by bar mizva date calculator (someone tell me how to make those entries a blue hyperlink), an applet taking into account place and time of birth.