You can manually add funds as often as you'd like to your Digit account!
To add funds:
1) Open the Digit app
2) Tap into the goal or fund you'd like to add money to
3) Tap the "Add Money" button at the bottom
4) Enter the desired amount to add
Once you've initiated and confirmed a transfer into your Rainy Day Fund, this transaction can take up to 3 business days before the funds are fully posted and can be withdrawn back to your checking account. Often this is faster, but please be certain before confirming the transfer.