Blue Ocean Date Values
Tag 75 always represents the calendar date on which the Blue Ocean trading session closes. This is referred to as the session date.
The session date identifies the trading session. For example, the 20250211 session opened at 8:00 PM ET on February 10, 2025 and closed at 4:00 AM ET on February 11, 2025. For clearance and settlement, this session carries a trade date of 20250211 and settles on 20250212.
The TRF trade date, by contrast, is based strictly on the actual trade timestamp in Eastern Time. Tag 75 does not convey that information.