Index: firmware/App/HDCommon.h
===================================================================
diff -u -r1a45eaee5e57add6f852e190a10cc8cf42672dc9 -r2ad92f55f437b3b293432f0aba70a5d70924f36b
--- firmware/App/HDCommon.h	(.../HDCommon.h)	(revision 1a45eaee5e57add6f852e190a10cc8cf42672dc9)
+++ firmware/App/HDCommon.h	(.../HDCommon.h)	(revision 2ad92f55f437b3b293432f0aba70a5d70924f36b)
@@ -40,6 +40,7 @@
     #define DISABLE_ALARM_AUDIO             1           // Disable alarm audio
 //    #define SKIP_POST                       1           // Skip POST tests - all pass
 //    #define DONT_SKIP_NV_POST               1           // Do not skip NV Data POST
+//    #define USE_LIBRARY_TIME_FUNCTIONS      1           // Use the C library functions mktime() and gmtime() for epoch<=>date conversions
     #define DISABLE_AIR_TRAP_LEVELING_ALARM 1           // Disable air trap level control alarms
 //    #define DISABLE_3WAY_VALVES             1           // Disable 3-way valves
 //    #define TST_3WAY_VALVES_ALWAYS_OPEN     1           // After POST and homing, open all 4 valves