diff --git a/libsigrok.h b/libsigrok.h
index 7f18d690..910e5245 100644
--- a/libsigrok.h
+++ b/libsigrok.h
@@ -179,6 +179,7 @@ enum {
 	SR_MQ_SOUND_PRESSURE_LEVEL,
 	SR_MQ_CARBON_MONOXIDE,
 	SR_MQ_RELATIVE_HUMIDITY,
+	SR_MQ_TIME,		/**< Time */
 };
 
 /** Values for sr_datafeed_analog.unit. */
@@ -267,6 +268,8 @@ enum {
 	/** Sound pressure level represented as a percentage of measurements
 	 * that were over a preset alarm level. */
 	SR_MQFLAG_SPL_PCT_OVER_ALARM = 0x10000,
+	/** Time is duration (as opposed to epoch, ...). */
+	SR_MQFLAG_DURATION = 0x20000,
 };
 
 struct sr_context;