Recurring profiles are created to be run in a certain window of time, monthly, weekly, yearly, etc.
In the example of a monthly recurring profile, if a profile is added to start on the 15th of this month, GiftWorks will remind the users on the 15th of the next month to process that transaction. GiftWorks looks to have a transaction for this recurring donation for every period (month).
Technically you could run it any time within the current month and satisfy the profile being run for this month. You would only be able to apply a donation to the next period when it changes to the next month. When You apply the transaction, it will update the period to the next month that it is expecting a payment. If this ever gets out of sync, you can use the 'Recurring Donations Profiles Current Period Update' to “re-sync” everything and get them back in the current periods.
Ideally this should not happen and all of the periods should be up to date.