diff --git a/GEOMS-TE-OPC-AEROSOL-001.csv b/GEOMS-TE-OPC-AEROSOL-001.csv
index e0a151e5f56356d9de1ac59d8771c850db9690eb..6128744302217e34c0fadf12a41905b2c0c4cf1f 100644
--- a/GEOMS-TE-OPC-AEROSOL-001.csv
+++ b/GEOMS-TE-OPC-AEROSOL-001.csv
@@ -1,6 +1,6 @@
 2,DATETIME,DATETIME,MJD2K,DOUBLE,Representative DateTime of measurement,x
-2,DATETIME.START,DATETIME,MJD2K,DOUBLE,Start DateTime of measurement,x
-2,DATETIME.STOP,DATETIME,MJD2K,DOUBLE,Stop DateTime of measurement,x
+2,DATETIME.START,DATETIME,MJD2K,DOUBLE,Start DateTime of measurement,o
+2,DATETIME.STOP,DATETIME,MJD2K,DOUBLE,Stop DateTime of measurement,o
 2,INTEGRATION.TIME,[CONSTANT|DATETIME],s,REAL,Effective/Actual integration time,o
 2,ALTITUDE,ALTITUDE,m,REAL,Geometric height calculated from the GPS,x
 2,LATITUDE,[CONSTANT|ALTITUDE|DATETIME],deg,REAL,In-situ GPS latitude of the instrument if reported otherwise launch geolocation,x