How often should a married couple with one baby have per week?

when you have a baby they take up so much time that by the time ur ready its either too late and hubby gotta go to sleep bec. hes waking up for work or neither of you are home at the same time when the baby is sleeping (he works in the day and go to school on evenings)...its very hard to have ! what do most people do? have any ideas?