If we start on April the 11th we will have 73 days before the draft... so while the early rounds can be 12 hours we will have to change the time period to shorter for the later round picks... just like the NHL do actually!
Maybe 12 hours for 1st & 2nd.
6 hours from 3rd-7th.
That would mean 1st & 2nd take 30 days.
3rd-7th would take 7.5 days a round, so 35 days overall.
And if people are not available for their picks (especially later ones) and know in advance they could do a write in top 3-5 choices in order or something. Makes it less hassle for everyone.
A 3PM Eastern start time is probably best as well... that would mean selection periods are:
3PM-3AM
3AM-3PM
in first two rounds, and then:
3PM-9PM
9PM-3AM
3AM-9AM
9AM-3PM
that means that everyone will have at least ~2 hours of 'sociable' time to pick... could shuffle to 4PM if people prefer would only really affect 9PM-3AM and 3AM-9AM slots. (changing them to 10PM-4AM and 4AM-10AM)