Testing HL7 v2 OBX-14: What Date/Time of the Observation Actually Needs to Handle
A message can carry several different timestamps for the same result — when it was collected, when it was reported, when the message was sent — and OBX-14 specifically marks when the observation itself was made, which is easy to confuse with the others if a mapping was built without checking which timestamp field it actually points to.
OBX-14 is the fourteenth field of the HL7 v2 OBX segment — it carries the date and time the individual observation was actually performed or measured, distinct from when the result was reported or the message was sent.
What this field contains
Example
202607261430 in OBX-14 marks when the potassium observation was performed — July 26, 2026 at 14:30. Synthetic result — not a real patient.
Where this trips people up
It is common for an integration to grab whatever timestamp field is easiest to reach in the message and label it as "result time" in a downstream system, without confirming it actually came from OBX-14 rather than the OBR-level specimen collection time or the MSH message timestamp. For time-sensitive values — a critical potassium during a code, or a trending vital sign — using the wrong timestamp can make a result appear more or less recent than it actually is, which matters when clinical decisions depend on how fresh the data is.