Unlike the majority on here it seems, we both work full time (having a cocker is expensive after all!) Dexter has been left alone for up to four hours since he was 13 weeks old.
We haven't had any problems with him, obviously in the beginning he had some accidents during the day but was fully house trained by five months.
He is penned off in our kitchen so has room to walk around freely and play with his toys. He loves a kong with frozen peanut butter, that keeps him occupied for hours!
He tends to use the time we are working to just chill out and then we play and walk and train around his alone times.
Good luck, it may take some getting used to but in my experience it hasn't had a detrimental effect on Dexter.