Try this...My kids (3 years + almost 11 months) don't sleep more than three hour shifts (max) at night and especially never after 6am. Which is a genetic absurdity and very frustrating, as neither me nor the wife are morning people. All we want to do between 6am and 9am is sleep. (the rest of the night too)
As a result of constant interrupted sleep (or lack of), my projected life span is likely shrinking every night (as we speak, actually). But I still love the buggers to bits.
Despite the cronic lack of previously precious things like good sleep, a private life, my own personal space, sex and energy, being a father is actually awesome. Which is something pre-dad me would never understand. Dad-me struggles to understand the concept too at times; that even with those important things missing, life is generally better with kids than it was without.
It will just be slightly shorter.
http://gro.co.uk/product/gro-clock/
Worked a treat for mine - they wouldn't get up until the sun showed (we set it later and later by 5 mins each morning until we reached the "don't take the tinkle" setting)