diff --git a/src/classes/PRunDataHandler.cpp b/src/classes/PRunDataHandler.cpp
index 97171de9..e12e8400 100644
--- a/src/classes/PRunDataHandler.cpp
+++ b/src/classes/PRunDataHandler.cpp
@@ -6154,7 +6154,7 @@ bool PRunDataHandler::DateToISO8601(string inDate, string &iso8601Date)
     return false;
 
   TString str("");
-  str.Form("%04d-%02d-%02d", 1900+tm.tm_year, tm.tm_mon, tm.tm_mday);
+  str.Form("%04d-%02d-%02d", 1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday);
 
   iso8601Date = str.Data();
 
@@ -6187,7 +6187,7 @@ void PRunDataHandler::SplitTimeDate(TString timeData, TString &time, TString &da
   }
 
   time = TString::Format("%02d:%02d:%02d", tm.tm_hour, tm.tm_min, tm.tm_sec);
-  date = TString::Format("%04d-%02d-%02d", tm.tm_year+1900, tm.tm_mon, tm.tm_mday);
+  date = TString::Format("%04d-%02d-%02d", tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday);
 }
 
 //--------------------------------------------------------------------------