Dzug has basically answered your question. I'll just try to add a bit more detail:
According to the Manchester airport website, the only airlines which fly this route are as follows:
American Airlines
BmiBaby
BA
FlyBe
http://www.manchesterairport.co.uk/app/Destina tions3?LETTER=J
American Airlines can be eliminated from that list because their flights are actually just 'code-share' flights, operated by BA.
Up until the end of October, BmiBaby don't have a flight to Jersey before 1400. (From 31st October onwards, they have flights out at 0900 on Tuesdays and 1015 on Wednesdays but then they don't have any suitable flights back):
http://www.bmibaby.com/bmibaby/en/index.aspx?p =46&cf=timetable
BA fly out at 1015 (arriving at 1145) but the aircraft turns round straight away and returns half an hour later:
http://www.britishairways.com
The Manchester Airport website states that the FlyBe only operate charter flights on this route. The FlyBe website shows that it is possible to make a scheduled booking but the outbound flight isn't until late afternoon and you have to change at Southampton.
If you've just got a business meeting, you could fly out at 1010 (arrive 1145) with BA and return at 1600 (arrive 1720) with BmiBaby. (You could come back slightly later with FlyBe but the change at Southampton adds a significant amount to both the journey time and the cost). However, unless you explore the possibility of changing flights elesewhere, it's not possible to fit in a pleasure trip within a day.
Chris