Function: dtmToDate()

dtmToDate(parts, options?): Date | undefined

Materialize an absolute-instant JS Date from DtmParts: only on explicit caller request. Truncated fields fill to their lowest legal value (month → January, day → 1, time → 0) for instant construction only; the value's stated precision still tells the truth.

Timezone resolution is honest:

• has an offset → the exact instant, using that offset;
• no offset + assumeOffsetMinutes supplied → that offset is applied;
• no offset + nothing supplied → undefined (never a silent UTC guess).

Returns undefined for an invalid value or an unresolvable zone; never throws.

Parameters

parts

DtmParts

options?

DtmToDateOptions = {}

Returns

Date | undefined

Example

import { parseDtm, dtmToDate } from "@cosyte/hl7";

dtmToDate(parseDtm("20250102153045-0500"))?.toISOString();
// "2025-01-02T20:30:45.000Z": exact, offset-derived

dtmToDate(parseDtm("20250102"));                       // undefined: refuses to guess the zone
dtmToDate(parseDtm("20250102"), { assumeOffsetMinutes: 0 })?.toISOString();
// "2025-01-02T00:00:00.000Z": caller explicitly assumed UTC