Post Date
The Post Date is the date\fiscal period to which the transaction posts to General Ledger. The date on which the transaction is posted does not affect when the activity will show in General Ledger; this is determined only by the date in the Post Date field.

Transaction Date
The Transaction Date, also referred to as the Document Date, is the date the transaction was created. The Transaction Date is normally either the original document date (i.e. the original invoice date) or the date the transaction was recorded in the database.

These two dates do not have to match, but transaction and post dates in different fiscal periods may cause sub-ledger reconciliation issues. Refer to the Reconciliation Guides for additional information: [Accounting for Nonprofits] [The Financial Edge].