Hi there
For a six week, A time is 1hr to 1hr and 15min. That includes, from eyes open to eyes shut.
Below is a general guide. Some los vary and get more/less.
Awake time for babies
Newborn 50-60 mins
1 month 60 mins-hour and 15
2 months 1 hour and 15 - 20 mins
3 months 1 hour and 20 - 30 mins
4 months 1 hour and 45 - 2 hours
5 months 2 hours - 2.25 hours
Late 5 months/early 6 months 2.25-2.5 hours
6.5 - 7 months 2.75-3 hours. Some are getting more.
8 - 10 months 3 - 4 hours. Some are getting more.
11 - 12 months 3.5 -4.5 hours. Some are getting more if moved early to 1 nap
As for becoming OT, OS plays a role. I would normally start wind down about 25min before-ie walking around the house, singing a lullaby etc. At six weeks, I remember my lo would easily become OT and the cause was normally because she was OS.
I believe the rule of thumb for many los is that a 45min nap equals UT and a 30min nap equals OT.
HTH