Offerings that do not require escrow or have a “minimum” raise amount (most Regulation D and Regulation A offerings) can close on a “real time” basis - accepting investors daily if required and paying out those funds within a few business days.
Offerings that do have a minimum raise amount (all Regulation Crowdfunding (CF) offerings, and some Regulation A or D offerings) may close on a monthly basis, though various contingencies may need to be met.