| Tag | Field Name | Data Type | Union Datatype | Description | Added | Depr. | Enums from tag |
|---|---|---|---|---|---|---|---|
| 205 | MaturityDay | DayOfMonth |
Day of month used in conjunction with MaturityMonthYear to specify the maturity date for SecurityType=FUT or SecurityType=OPT. | Added FIX.4.1 |
|