diff --git a/libraries/AP_Mount/AP_Mount_Viewpro.cpp b/libraries/AP_Mount/AP_Mount_Viewpro.cpp
index 3b03d7c8a5..07608d689b 100644
--- a/libraries/AP_Mount/AP_Mount_Viewpro.cpp
+++ b/libraries/AP_Mount/AP_Mount_Viewpro.cpp
@@ -668,6 +668,7 @@ bool AP_Mount_Viewpro::send_m_ahrs()
         return false;
     }
 
+#if AP_RTC_ENABLED
     // get date and time
     uint16_t year, ms;
     uint8_t month, day, hour, min, sec;
@@ -676,6 +677,10 @@ bool AP_Mount_Viewpro::send_m_ahrs()
     }
     uint16_t date = ((year-2000) & 0x7f) | (((month+1) & 0x0F) << 7) | ((day & 0x1F) << 11);
     uint64_t second_hundredths = (((hour * 60 * 60) + (min * 60) + sec) * 100) + (ms * 0.1);
+#else
+    const uint16_t date = 0;
+    const uint64_t second_hundredths = 0;
+#endif
 
     // get vehicle velocity in m/s in NED Frame
     Vector3f vel_NED;
diff --git a/libraries/AP_Mount/AP_Mount_Xacti.cpp b/libraries/AP_Mount/AP_Mount_Xacti.cpp
index 695b65552d..9f210993d4 100644
--- a/libraries/AP_Mount/AP_Mount_Xacti.cpp
+++ b/libraries/AP_Mount/AP_Mount_Xacti.cpp
@@ -502,9 +502,14 @@ void AP_Mount_Xacti::handle_gnss_status_req(AP_DroneCAN* ap_dronecan, const Cana
     // get date and time
     uint16_t year, ms;
     uint8_t month, day, hour, min, sec;
+#if AP_RTC_ENABLED
     if (!AP::rtc().get_date_and_time_utc(year, month, day, hour, min, sec, ms)) {
         year = month = day = hour = min = sec = 0;
     }
+#else
+    year = month = day = hour = min = sec = 0;
+    (void)ms;
+#endif
 
     // send xacti specific gnss status message
     com_xacti_GnssStatus xacti_gnss_status_msg {};
@@ -938,9 +943,14 @@ bool AP_Mount_Xacti::set_datetime(uint32_t now_ms)
     // get date and time
     uint16_t year, ms;
     uint8_t month, day, hour, min, sec;
+#if AP_RTC_ENABLED
     if (!AP::rtc().get_date_and_time_utc(year, month, day, hour, min, sec, ms)) {
         return false;
     }
+#else
+    (void)ms;
+    return false;
+#endif
 
     // date time is of the format YYYYMMDDHHMMSS (14 bytes)
     // convert month from 0~11 to 1~12 range