The whole first year or so for my son, we did not get blood wrok done until afternoon.  whether or not this was right and the effects of doing so, I cannot say.  Because my son was such a hard one to get blood, we went to the Outpatient Surgery area of our hospital during their least busy times and they drew the blood.  That allowed very skilled personel and access to Neonatal nurses and out of normal areas to draw the blood.

Later, we started going in the am.  Our lab does not open until 7am..  I do not give meds and I get there early so that we can be one of the first to sign in.  I would also ask the lab which days are least heavy.  I rarely go on Mondays for that reason.  Because I put Emla cream on my son before we go, I start to nag them about the time if necessary.  They would rather have a numb and compliant 7 yr old that the alternative!!!