diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 325327a33a14de1522aca874d3d8ef70bb2c9738..f5a63ad8357d5358c657c14a75fc1cfab02cc484 100644
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -1550,6 +1550,7 @@ class Instrument:
             logger.debug("Writing metadata and physics time dataset to '%s'", output)
 
             self.write_metadata(hdf5)
+            hdf5['t'] = self.t
             hdf5['physics_t'] = self.physics_t
             hdf5['telemetry_t'] = self.telemetry_t