With newborns - 4/5 months, you time getting out and about during nap times as they can fall asleep in pushchair/stroller/carseat.
With 4/5 months+ you can time getting out and about either during nap times or 'A' times.
If your baby does not sleep properly during nap times, while out and about or you are going to be out all day, many mums make a point of staying in the next 1 or 2 days to get them back into the routine of sleeping in the cot/crib to catch up on some sleep.
Just click on the link, here is some more info
https://babywhispererforums.com/index.php?topic=56396.0
