There are 2 ways to achieve this, both of them are not completely automatic and are based on assumption that your time period is only 2 days.
First way is to use ITA Matrix, which allows you to choose 2-5 days for both departure and arrival:
Unfortunately, preferred times are rather limited there, so we won't use them. Instead you can use "Time bars" view and visually filter out some flights (red lines are mine):
However, you cannot buy a ticket at ITA website, so you will have to buy it somewhere else (e.g. other flight search website, airline website, travel agents).
Second way is to enumerate all possible combinations:
Depart on Sunday, arrive on Sunday;
Depart on Sunday, arrive on Monday;
Depart on Monday, arrive on Monday.
That is you do 3 searches instead of 1.
Most flight search sites allow to filter out flights by time (for example, Google Flights), so you can enforce 6am departure on Sunday or 9am arrival on Monday in corresponding searches.