DerivativeMaturityMonthYear (FIX tag 1251)
DerivativeMaturityMonthYear (tag 1251) is a MonthYear field defined in FIX 5.0 SP2. It appears in 3 message types, always optionally.
At a glance
- Tag
- 1251
- Name
- DerivativeMaturityMonthYear
- Datatype
- MonthYear (String)
- Format
- YYYYMM[DD|WW]
- Dialects
- FIX 5.0 SP2
- Messages
- 3
What the specification says
Month and Year of the maturity (used for standardized futures and options).
Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.
A real message using tag 1251
| Tag | Field | Wire value | Meaning |
|---|---|---|---|
| 8 | BeginString | FIXT.1.1 | |
| 9 | BodyLength | 93 | |
| 35 | MsgType | z | DerivativeSecurityListRequest |
| 49 | SenderCompID | BOARTEAM | |
| 56 | TargetCompID | COUNTERPARTY | |
| 34 | MsgSeqNum | 2 | |
| 52 | SendingTime | 20240101-12:00:00.000 | |
| 320 | SecurityReqID | EXAMPLE | |
| 559 | SecurityListRequestType | 0 | Symbol |
| 1251 | DerivativeMaturityMonthYear | 202401 | |
| 10 | CheckSum | 105 |
Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.
Generated from the FIX 5.0 SP2 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.
Where tag 1251 appears
Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.
| Message | MsgType | Requiredness | Where in the message |
|---|---|---|---|
| DerivativeSecurityList | AA | Optional | inside DerivativeSecurityDefinition › DerivativeInstrument |
| DerivativeSecurityListRequest | z | Optional | inside the DerivativeInstrument component |
| DerivativeSecurityListUpdateReport | BR | Optional | inside DerivativeSecurityDefinition › DerivativeInstrument |
Wire format
A month, optionally with a day or week — the format pattern shows which forms are legal. @boarteam/fix keeps the value as a string; format rules are checked by validate(), which reports validate/invalid-value rather than throwing.
Read tag 1251 in TypeScript
import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix50sp2";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[1251];field?.name; // "DerivativeMaturityMonthYear"field?.raw; // the verbatim wire stringfield?.value; // coerced to a stringOther MonthYear fields
Decode this in your own code
The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.
npm i @boarteam/fix @boarteam/fix-dict-fix50sp2