Teaching hours are set in Pakistan time, which is 10 hours ahead of New York in winter and 9 hours ahead in summer. On weekdays that puts lessons between 5 am and 1 pm Eastern time (6 am to 2 pm in summer). In Chicago it is 4 am to noon, in Denver 3 to 11 am and in Los Angeles 2 to 10 am, each an hour later in summer. US afternoons and evenings fall outside teaching hours, so after-school lessons are not possible.
For school-age children that leaves two good options. A 30-minute lesson at 6:30 or 7 am fits before the school bus in every mainland time zone. Or take lessons at the weekend: on the East Coast the Saturday and Sunday window runs from midnight to noon in winter, so a 9 or 10 am lesson after breakfast is easy to keep. On the West Coast it runs from 9 pm on Friday and Saturday evenings until 9 am the next morning (10 pm to 10 am in summer).
Homeschooling families and adults with free mornings can use any weekday slot. In the coming years Ramadan falls in late winter, when iftar on the East Coast is between about 5 and 6 pm. That is after teaching hours end, so keep a morning or weekend lesson through the month and agree the Ramadan times a few weeks before it starts.
Most American children are at school from around 8 am until 3 pm on weekdays. Weekend: Saturday and Sunday.