UnderlyingMaturityDay (FIX tag 314)

DayOfMonthFIX 4.2

UnderlyingMaturityDay (tag 314) is a DayOfMonth field defined in FIX 4.2. It appears in 4 message types, always optionally.

At a glance

Tag
314
Name
UnderlyingMaturityDay
Datatype
DayOfMonth (int)
Dialects
FIX 4.2
Messages
4

What the specification says

Underlying security’s MaturityDay. See MaturityDay field for description

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 314

SecurityDefinitionRequest · FIX 4.2
TagFieldWire valueMeaning
8BeginStringFIX.4.2
9BodyLength123
35MsgTypecSecurity Definition Request
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
320SecurityReqIDEXAMPLE
321SecurityRequestType0Request Security identity and specifications
146NoRelatedSym2 entries2repeating group
311UnderlyingSymbolEXAMPLE
314UnderlyingMaturityDay1
311UnderlyingSymbolEXAMPLE
314UnderlyingMaturityDay1
10CheckSum198
Edit and decode it yourself

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.

Open in the full decoder →

Generated from the FIX 4.2 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 314 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.

MessageMsgTypeRequirednessWhere in the message
MassQuoteiOptionaldirectly on the message body
QuoteAcknowledgementbOptionaldirectly on the message body
SecurityDefinitiondOptionaldirectly on the message body
SecurityDefinitionRequestcOptionaldirectly on the message body

Wire format

A day number within a month, 1–31. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 314 in TypeScript

decode.tsts
import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix42";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[314];field?.name;   // "UnderlyingMaturityDay"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Other DayOfMonth 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-fix42