Sleeping during the day

lsmithk2

My LO is 6 weeks and sometimes sleeps what feels like all day.  Yesterday he was up and fussy all day until I finally got him down to sleep for the night at 11pm and then he slept until 3am, fed and up at 6 and again to feed at 8:45.  So he's slept from 10:30-1 and then up to feed from 1:15-2 and then back asleep at 2 and is currently sleeping right now.  Will all this sleeping mess up his sleeping at night?  How long do you let your baby sleep during the day?