diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c6ce5f47b..f0dfd72d56 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,10 @@ All notable changes to the Zowe Installer will be documented in this file.
 
 #### Minor enhancements/defect fixes
 
+## `2.13.0`
+#### Minor enhancements/defect fixes
+- Enhancement: `/bin/utils/date-add.rex` utility is accepting the date formatting as combination of YY|YYYY, MM, DD and any separator.
+
 ## `2.11.0`
 
 ### New features and enhancements
diff --git a/bin/libs/certificate.sh b/bin/libs/certificate.sh
index d323d4f25a..49fcc232ef 100644
--- a/bin/libs/certificate.sh
+++ b/bin/libs/certificate.sh
@@ -884,8 +884,8 @@ EOF
   fi
 
   date_add_util="${ZWE_zowe_runtimeDirectory}/bin/utils/date-add.rex"
-  validity_ymd=$("${date_add_util}" ${validity} 1234-56-78)
-  validity_mdy=$("${date_add_util}" ${validity} 56/78/34)
+  validity_ymd=$("${date_add_util}" ${validity} YYYY-MM-DD)
+  validity_mdy=$("${date_add_util}" ${validity} MM/DD/YY)
 
   # option 2 needs further changes on JCL
   racf_connect1="s/dummy/dummy/"
diff --git a/bin/utils/date-add.rex b/bin/utils/date-add.rex
index c8f3649a3e..bf6b0d120d 100755
--- a/bin/utils/date-add.rex
+++ b/bin/utils/date-add.rex
@@ -13,19 +13,58 @@
 
 /*
  * Parameters:
- *   1: how many days in the future
- *   2: date format.
- *      For example, 1234-56-78 will be YYYY-MM-DD.
- *      For example, 56/78/34 will be MM/DD/YY.
+ *   1: days: how many days in the future or past
+ *        negative number for past
+ *   2: dformat: date format
+ *        Combination of YY|YYYY, MM and DD and (optional) any separator
+ *        For example: YYYY-MM-DD, MM/DD/YY, DD.MM.YY, YYMMDD...
  *
- * Example: date-add.rexx 7 1234-56-78
+ * Examples:
+ *   date-add.rex 7 YYYY-MM-DD
+ *   date-add.rex -1 MM/DD/YY
  */
 
 arg options
-parse var options days format
+parse upper var options days dformat
 
-today = Date('Base')
+ERR_DATE.1 = "YY or YYYY (year)"
+ERR_DATE.2 = "MM (month)"
+ERR_DATE.3 = "DD (day)"
+
+if datatype(days) \= "NUM" then do
+  say "ERROR: expected numeric value for days: '"days"'"
+  exit 1
+end
+/* YYMMDD -> YYYY/MM/DD */
+if length(dformat) < 6 | length(dformat) > 10 then do
+  len = 'short'
+  if length(dformat) > 10 then
+    len = 'long'
+  say "ERROR: invalid date format: '"||dformat||"' is too "||len
+  exit 1
+end
+else do i = 1 to 3
+  if pos(word(ERR_DATE.i, 1), dformat) = 0 then do
+    say "ERROR: invalid date format: '"||dformat||,
+        "' is missing "||ERR_DATE.i
+    exit 1
+  end
+end
+
+today = Date("Base")
 target = today + days
-ISOTarget = Date('Standard', target, 'Base')
-result = Translate(format, ISOTarget, '12345678')
-say result
+ISOTarget = Date("Standard", target, "Base")
+
+/* ISOTarget YYYYMMDD                                  */
+/*           12344578 => YYYY = 1234, MM = 56, DD = 78 */
+
+if pos("YYYY", dformat) = 0 then
+  dformat = overlay("34", dformat, pos("YY", dformat))
+else
+  dformat = overlay("1234", dformat, pos("YYYY", dformat))
+dformat = overlay("56", dformat, pos("MM", dformat))
+dformat = overlay("78", dformat, pos("DD", dformat))
+
+res = translate(dformat, ISOTarget, "12345678")
+say res
+exit 0