Reference·EVN Segment·EVN-2
HL7 v2 Reference

HL7 v2 EVN-2 (Recorded Date/Time): Format, Values, and Testing Notes

Jul 27, 2026 · 4 min read
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Of every field in EVN, EVN-2 is the one your interface engine is most likely to log, sort, and alert on, so getting its format wrong breaks more than one downstream system.

Quick answer

EVN-2 (Recorded Date/Time) is a timestamp marking when the sending application logged the triggering event, expressed in HL7's standard YYYYMMDDHHMMSS format, optionally with a timezone offset. It is functionally the "as of" clock for the message and is frequently used by receiving systems to sequence events, detect out-of-order delivery, or drive SLA alerting. Because it is so heavily relied on operationally, test suites should exercise edge cases like missing seconds, missing timezone offsets, and midnight-boundary rollovers.

What this field contains

YYYYMMDD
Date-only precision — technically valid but rare in production; some receivers reject it if they expect full precision
YYYYMMDDHHMM
Minute precision — common from older interfaces that do not track seconds
YYYYMMDDHHMMSS
Full precision — the most common format seen in modern ADT feeds and the safest default for synthetic test data
+/-ZZZZ suffix
Timezone offset — optional but important in multi-facility deployments spanning time zones; absence often defaults to local server time

Example

Synthetic example Generated by Synthibase
EVN|A01|20260726073000||ADM|8842^REYES^MONICA^L^^^MD|20260726072500

EVN-2 shows 20260726073000, meaning the event was recorded at 7:30:00 AM on July 26, 2026.

Where this trips people up

Teams frequently build test data with a fixed-width timestamp and never test what happens when a real sender omits seconds or the timezone offset. Interface engines vary wildly here: some pad missing components with zeros, others reject the message outright. If your regression suite only ever sends full-precision, offset-included timestamps, you will not find out your parser mishandles a minute-precision EVN-2 until a legacy feed sends one in production.

HL7 v2 EVN Segment Guide: Fields, Format, and Testing Gotchas
HL7 ADT Messages: A01 through A08 Explained
Regression Testing for EHR Upgrades: A Complete Guide
Exercise every timestamp format your feeds actually use
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