If you need to run a report on all postings happened in GL on a specific date, you can use a SmartList report. There is a field in GP, called Originating Posted Date that tracks a system date when a transaction was entered and posted, not a trx posting date you can modify.
Go to Microsoft Dynamics GP -> SmartList
• Expand Account Transactions
• Click *
• Click Columns
• Click Add and lookup for an Originating Posted Date
• Click Ok and Ok one more time
• Click Search and pull up a Originating Posted Date and set it equal to your date.
SmartList will generate a list of transactions that were posted that day.