diff --git a/LibOneM2M/OneM2M_Functions.ttcn b/LibOneM2M/OneM2M_Functions.ttcn
index 0bcd2770ce7f0aad0515df15410da0cb353faec7..67bfdafaf44ff4865c72798f77f972406514fcae 100644
--- a/LibOneM2M/OneM2M_Functions.ttcn
+++ b/LibOneM2M/OneM2M_Functions.ttcn
@@ -3459,7 +3459,7 @@ module OneM2M_Functions {
 		 * @param p_timestamp Given timestamp
 		 * @return Year
 		 */
-		function f_getYear(charstring p_timestamp) runs on Tester return charstring {
+		function f_getYear(charstring p_timestamp) runs on Tester return integer {
 			
 			var charstring v_year := "";
 			var integer i;
@@ -3467,7 +3467,7 @@ module OneM2M_Functions {
 			for(i := 0; i <= 3; i := i+1){
 				v_year := v_year & p_timestamp[i];
 			}
-			return v_year;
+			return str2int(v_year);
 			
 		} // end f_getYear
 		
@@ -3476,7 +3476,7 @@ module OneM2M_Functions {
 		 * @param p_timestamp Given timestamp
 		 * @return Year
 		 */
-		function f_getMonth(charstring p_timestamp) runs on Tester return charstring {
+		function f_getMonth(charstring p_timestamp) runs on Tester return integer {
 			
 			var charstring v_month := "";
 			var integer i;
@@ -3486,7 +3486,7 @@ module OneM2M_Functions {
 					v_month := v_month & p_timestamp[i];
 				}
 			}
-			return v_month;
+			return str2int(v_month);
 			
 		} // end f_getYear
 		
diff --git a/OneM2M_PermutationFunctions.ttcn b/OneM2M_PermutationFunctions.ttcn
index 088debddf908a588581dd93eef6425eea7bf332b..b42f331bc1b6ff8a386ea1c3b5569b13b47a4c72 100644
--- a/OneM2M_PermutationFunctions.ttcn
+++ b/OneM2M_PermutationFunctions.ttcn
@@ -5844,7 +5844,7 @@ module OneM2M_PermutationFunctions {
 							// Preamble
 							v_createRequest := f_getCreateRequestPrimitive(int1, m_createAcpBase, -1);
 							v_currentTime := fx_generateTimestamp();
-							v_accessControlRule.accessControlContexts_list := {{{"* * * * " & f_getMonth(v_currentTime) & " *"}, omit, omit}};
+							v_accessControlRule.accessControlContexts_list := {{{"* * * * " & int2str(f_getMonth(v_currentTime)) & " *"}, omit, omit}};
 							v_createRequest.primitiveContent.accessControlPolicy.privileges.accessControlRule_list := {v_accessControlRule};
 							vc_acpAuxIndex := f_cse_createResource(int1, v_createRequest); // CSE child resource
 							
@@ -5892,7 +5892,7 @@ module OneM2M_PermutationFunctions {
 						function f_CSE_SEC_ACP_006(template RequestPrimitive p_requestPrimitive, in ResponseStatusCode p_responseStatusCode) runs on AeSimu{
 							// Local variables
 							var MsgIn v_response;
-							var charstring v_month;
+							var integer v_month;
 							var charstring v_currentTime;
 							var integer v_aeIndex := -1;
 							var RequestPrimitive v_createRequest;
@@ -5909,12 +5909,12 @@ module OneM2M_PermutationFunctions {
 							v_createRequest := f_getCreateRequestPrimitive(int1, m_createAcpBase, -1);
 							v_currentTime := fx_generateTimestamp();
 							v_month := f_getMonth(v_currentTime);
-							if(v_month =="12") {
-								v_month := "1";
+							if(v_month == 12) {
+								v_month := 1;
 							} else {
-								v_month := int2char(char2int(v_month) + 1);
+								v_month := v_month + 1;
 							}
-							v_accessControlRule.accessControlContexts_list := {{{"* * * * " & v_month & " *"}, omit, omit}};
+							v_accessControlRule.accessControlContexts_list := {{{"* * * * " & int2str(v_month) & " *"}, omit, omit}};
 							v_createRequest.primitiveContent.accessControlPolicy.privileges.accessControlRule_list := {v_accessControlRule};
 							vc_acpAuxIndex := f_cse_createResource(int1, v_createRequest); // CSE child resource