We track donations made via each store and charge the merchant's credit card on file when $50 in donations is accrued or 30 days has passed, whichever happens first.
Those donations are disbursed to the nonprofits within the first 10 days of the following month (so donations made in January will be sent to the nonprofits by February 10th).
For donations outside the US: we work though international charitable donation processors and due to minimum fees, do not send them donations for regranting to a specific organization until there a minimum $500 in donations for that organization. This can substantially delay delivery of the funds, but the benefit is reduced fees.
The Pledgeling Foundation support site (link) has answers to many questions about how funds flow to nonprofit charitable organizations.