diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8c2916b8..56a4b9a2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,12 @@
 All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
+## [2.125.3](https://github.com/open-horizon/exchange-api/pull/730) - 2024-11-04
+- issue 594: Rework unit-test for ApiUtilsSuite.
+- Split ApiUtilsSuite in two tests: TestApiUtilsTime and TestNodeAgbotTokenValidation.
+- Extend number of tests for TestApiUtilsTime and TestNodeAgbotTokenValidation.
+- Add validation for invalid time format.
+
 ## [2.125.2](https://github.com/open-horizon/exchange-api/pull/726) - 2024-10-31
 - issue 607: Rework unit-test for version.
 - Increased the number of test cases to cover corner cases for Version.
diff --git a/src/main/resources/version.txt b/src/main/resources/version.txt
index 394b36fa..01a32c8b 100644
--- a/src/main/resources/version.txt
+++ b/src/main/resources/version.txt
@@ -1 +1 @@
-2.125.2
+2.125.3
diff --git a/src/main/scala/org/openhorizon/exchangeapi/utility/ApiTime.scala b/src/main/scala/org/openhorizon/exchangeapi/utility/ApiTime.scala
index e6a4cb56..be330481 100644
--- a/src/main/scala/org/openhorizon/exchangeapi/utility/ApiTime.scala
+++ b/src/main/scala/org/openhorizon/exchangeapi/utility/ApiTime.scala
@@ -1,4 +1,5 @@
 package org.openhorizon.exchangeapi.utility
+import java.time.format.DateTimeParseException
 
 import java.time.{Instant, ZoneId, ZonedDateTime}
 
@@ -48,7 +49,21 @@ object ApiTime {
     (nowSeconds - thenTime >= secondsStale)
   }
   
+  /** Validates time format */
+  def isValidTimeFormat(time: String): Boolean = {
+    try {
+      ZonedDateTime.parse(time)
+      true
+    } catch {
+      case _: DateTimeParseException => false
+      case _: Exception => false
+    }
+  }
+  
   def fixFormatting(time: String): String = {
+    if (time.isEmpty || !isValidTimeFormat(time)) {
+      return "Invalid format"
+    }
     val timeLength: Int = time.length
     /*
      This implementation uses length of the string instead of a regex to make it as fast as possible
diff --git a/src/test/scala/org/openhorizon/exchangeapi/ApiUtilsSuite.scala b/src/test/scala/org/openhorizon/exchangeapi/ApiUtilsSuite.scala
deleted file mode 100644
index f4cd4826..00000000
--- a/src/test/scala/org/openhorizon/exchangeapi/ApiUtilsSuite.scala
+++ /dev/null
@@ -1,80 +0,0 @@
-package org.openhorizon.exchangeapi
-
-import org.junit.runner.RunWith
-import org.openhorizon.exchangeapi.utility.{ApiTime, NodeAgbotTokenValidation}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatestplus.junit.JUnitRunner
-
-@RunWith(classOf[JUnitRunner])
-class ApiUtilsSuite extends AnyFunSuite{
-
-  test("ApiTime fixFormatting no milliseconds"){
-    val timeNoMilliseconds = "2019-06-17T21:24:55Z[UTC]"
-    info(ApiTime.fixFormatting(timeNoMilliseconds) + " , " + "2019-06-17T21:24:55.000Z[UTC]")
-    assert(ApiTime.fixFormatting(timeNoMilliseconds) == "2019-06-17T21:24:55.000Z[UTC]")
-  }
-
-  test("ApiTime fixFormatting no seconds and nomilliseconds"){
-    val timeNoSeconds = "2019-06-17T21:24Z[UTC]"
-    info(ApiTime.fixFormatting(timeNoSeconds) + " , " + "2019-06-17T21:24:00.000Z[UTC]")
-    assert(ApiTime.fixFormatting(timeNoSeconds) == "2019-06-17T21:24:00.000Z[UTC]")
-  }
-
-  test("ApiTime.nowUTC is always right length"){
-    info(ApiTime.nowUTC)
-    assert(ApiTime.nowUTC.length >= 29)
-  }
-
-  test("ApiTime.thenUTC is always right time and length"){
-    info(ApiTime.thenUTC(1615406509)+ " , 2021-03-10T20:01:49.000Z[UTC]")
-    assert(ApiTime.thenUTC(1615406509) == "2021-03-10T20:01:49.000Z[UTC]")
-    assert(ApiTime.thenUTC(1615406509).length >= 29)
-  }
-
-  test("ApiTime.thenUTC is always right time and length test 2"){
-    info(ApiTime.thenUTC(1615406355)+ " , 2021-03-10T19:59:15.000Z[UTC]")
-    assert(ApiTime.thenUTC(1615406355) == "2021-03-10T19:59:15.000Z[UTC]")
-    assert(ApiTime.thenUTC(1615406355).length >= 29)
-  }
-
-  test("ApiTime.pastUTC is always right length"){
-    info(ApiTime.pastUTC(10))
-    assert(ApiTime.pastUTC(10).length >= 29)
-  }
-
-  test("ApiTime.futureUTC is always right length"){
-    info(ApiTime.futureUTC(10))
-    assert(ApiTime.futureUTC(10).length >= 29)
-  }
-
-  test("ApiTime.beginningUTC is always correct and right length"){
-    info(ApiTime.beginningUTC + " , " +"1970-01-01T00:00:00.000Z[UTC]")
-    assert(ApiTime.beginningUTC == "1970-01-01T00:00:00.000Z[UTC]")
-    assert(ApiTime.beginningUTC.length >= 29)
-  }
-
-  test("NodeAgbotTokenValidation.isValid correctly identifies if password is too short, <15 chars"){
-    info("NodeAgbotTokenValidation.isValid(\"1Abbb\")"+ " , " + NodeAgbotTokenValidation.isValid("1Abbb").toString())
-    assert(NodeAgbotTokenValidation.isValid("1Abbb") == false)
-  }
-
-  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain digit"){
-    info("NodeAgbotTokenValidation.isValid(\"aaaaaaaaaaaaaaaB\")"+ " , " + NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaaB").toString())
-    assert(NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaaB") == false)
-  }
-
-  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain uppercase letter"){
-    info("NodeAgbotTokenValidation.isValid(\"aaaaaaaaaaaaaaa1\")"+ " , " + NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaa1").toString())
-    assert(NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaa1") == false)
-  }
-
-  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain lowercase letter"){
-    info("NodeAgbotTokenValidation.isValid(\"AAAAAAAAAAAAAB1\")"+ " , " + NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAAB1").toString())
-    assert(NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAAB1") == false)
-  }
-
-  test("NodeAgbotTokenValidation.isValid correctly identifies valid password"){
-    info("NodeAgbotTokenValidation.isValid(\"AAAAAAAAAAAAaB1\")"+ " , " + NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAaB1").toString())
-    assert(NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAaB1") == true)
-  }
-}
diff --git a/src/test/scala/org/openhorizon/exchangeapi/utility/apiutils/TestApiUtilsTime.scala b/src/test/scala/org/openhorizon/exchangeapi/utility/apiutils/TestApiUtilsTime.scala
new file mode 100644
index 00000000..be80e65a
--- /dev/null
+++ b/src/test/scala/org/openhorizon/exchangeapi/utility/apiutils/TestApiUtilsTime.scala
@@ -0,0 +1,100 @@
+package org.openhorizon.exchangeapi
+
+import org.openhorizon.exchangeapi.utility.{ApiTime}
+import org.scalatest.funsuite.AnyFunSuite
+
+object DateTimeConstants {
+  val DateTimePattern: String = """\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{1,9}Z\[UTC\]"""
+  val TimeLength: Int = 29
+}
+
+class TestApiUtilsTime extends AnyFunSuite {
+  test("ApiTime fixFormatting no milliseconds") {
+    val timeNoMilliseconds = "2019-06-17T21:24:55Z[UTC]"
+    info(ApiTime.fixFormatting(timeNoMilliseconds) + " , " + "2019-06-17T21:24:55.000Z[UTC]")
+    assert(ApiTime.fixFormatting(timeNoMilliseconds) == "2019-06-17T21:24:55.000Z[UTC]")
+  }
+
+  test("ApiTime fixFormatting no seconds and no milliseconds") {
+    val timeNoSeconds = "2019-06-17T21:24Z[UTC]"
+    info(ApiTime.fixFormatting(timeNoSeconds) + " , " + "2019-06-17T21:24:00.000Z[UTC]")
+    assert(ApiTime.fixFormatting(timeNoSeconds) == "2019-06-17T21:24:00.000Z[UTC]")
+  }
+
+  test("ApiTime fixFormatting handles invalid format") {
+    val invalidTime = "invalid-time-format"
+    info(ApiTime.fixFormatting(invalidTime) + " , " + "Invalid format")
+    assert(ApiTime.fixFormatting(invalidTime) == "Invalid format")
+  }
+
+  test("ApiTime.nowUTC is always right length") {
+    info(ApiTime.nowUTC)
+    assert(ApiTime.nowUTC.length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.nowUTC returns current time in valid format") {
+    val currentTime = ApiTime.nowUTC
+    info(currentTime)
+    assert(currentTime.matches(DateTimeConstants.DateTimePattern))
+  }
+
+  test("ApiTime.thenUTC is always right time and length") {
+    info(ApiTime.thenUTC(1615406509) + " , 2021-03-10T20:01:49.000Z[UTC]")
+    assert(ApiTime.thenUTC(1615406509) == "2021-03-10T20:01:49.000Z[UTC]")
+    assert(ApiTime.thenUTC(1615406509).length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.thenUTC is always right time and length test 2"){
+    info(ApiTime.thenUTC(1615406355)+ " , 2021-03-10T19:59:15.000Z[UTC]")
+    assert(ApiTime.thenUTC(1615406355) == "2021-03-10T19:59:15.000Z[UTC]")
+    assert(ApiTime.thenUTC(1615406355).length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.thenUTC handles future timestamps") {
+    val futureTimestamp = System.currentTimeMillis() / 1000 + 10000
+    val futureTime = ApiTime.thenUTC(futureTimestamp)
+    info(futureTime)
+    assert(futureTime.length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.thenUTC handles past timestamps") {
+    val pastTimestamp = System.currentTimeMillis() / 1000 - 10000
+    val pastTime = ApiTime.thenUTC(pastTimestamp)
+    info(pastTime)
+    assert(pastTime.length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.pastUTC is always right length") {
+    info(ApiTime.pastUTC(10))
+    assert(ApiTime.pastUTC(10).length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.pastUTC returns correct time") {
+    val tenSecondsAgo = ApiTime.pastUTC(10)
+    info(tenSecondsAgo)
+    assert(tenSecondsAgo.matches(DateTimeConstants.DateTimePattern))
+  }
+
+  test("ApiTime.futureUTC is always right length") {
+    info(ApiTime.futureUTC(10))
+    assert(ApiTime.futureUTC(10).length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.futureUTC returns correct time") {
+    val tenSecondsLater = ApiTime.futureUTC(10)
+    info(tenSecondsLater)
+    assert(tenSecondsLater.matches(DateTimeConstants.DateTimePattern))
+  }
+
+  test("ApiTime.beginningUTC is always correct and right length") {
+    info(ApiTime.beginningUTC + " , " + "1970-01-01T00:00:00.000Z[UTC]")
+    assert(ApiTime.beginningUTC == "1970-01-01T00:00:00.000Z[UTC]")
+    assert(ApiTime.beginningUTC.length >= DateTimeConstants.TimeLength)
+  }
+
+  test("ApiTime.beginningUTC is formatted correctly") {
+    val beginningTime = ApiTime.beginningUTC
+    info(beginningTime)
+    assert(beginningTime.matches(DateTimeConstants.DateTimePattern))
+  }
+}
diff --git a/src/test/scala/org/openhorizon/exchangeapi/utility/tokenvalidation/TestNodeAgbotTokenValidation.scala b/src/test/scala/org/openhorizon/exchangeapi/utility/tokenvalidation/TestNodeAgbotTokenValidation.scala
new file mode 100644
index 00000000..5c5ca6c1
--- /dev/null
+++ b/src/test/scala/org/openhorizon/exchangeapi/utility/tokenvalidation/TestNodeAgbotTokenValidation.scala
@@ -0,0 +1,63 @@
+package org.openhorizon.exchangeapi
+
+import org.openhorizon.exchangeapi.utility.{NodeAgbotTokenValidation}
+import org.scalatest.funsuite.AnyFunSuite
+
+
+class TestNodeAgbotTokenValidation extends AnyFunSuite {
+  test("NodeAgbotTokenValidation.isValid correctly identifies if password is too short, <15 chars"){
+    info("NodeAgbotTokenValidation.isValid(\"1Abbb\")"+ " , " + NodeAgbotTokenValidation.isValid("1Abbb").toString())
+    assert(NodeAgbotTokenValidation.isValid("1Abbb") == false)
+    info("NodeAgbotTokenValidation.isValid(\"1Abcdefghijkl\")"+ " , " + NodeAgbotTokenValidation.isValid("1Abcdefghijkl").toString())
+    assert(NodeAgbotTokenValidation.isValid("1Abcdefghijkl") == false)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain digit"){
+    info("NodeAgbotTokenValidation.isValid(\"aaaaaaaaaaaaaaaB\")"+ " , " + NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaaB").toString())
+    assert(NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaaB") == false)
+    info("NodeAgbotTokenValidation.isValid(\"abcdefghijklmno\")"+ " , " + NodeAgbotTokenValidation.isValid("abcdefghijklmno").toString())
+    assert(NodeAgbotTokenValidation.isValid("abcdefghijklmno") == false)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain uppercase letter"){
+    info("NodeAgbotTokenValidation.isValid(\"aaaaaaaaaaaaaaa1\")"+ " , " + NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaa1").toString())
+    assert(NodeAgbotTokenValidation.isValid("aaaaaaaaaaaaaaa1") == false)
+    info("NodeAgbotTokenValidation.isValid(\"abcdefghijklmno1\")"+ " , " + NodeAgbotTokenValidation.isValid("abcdefghijklmno1").toString())
+    assert(NodeAgbotTokenValidation.isValid("abcdefghijklmno1") == false)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies if password does not contain lowercase letter"){
+    info("NodeAgbotTokenValidation.isValid(\"AAAAAAAAAAAAAB1\")"+ " , " + NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAAB1").toString())
+    assert(NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAAB1") == false)
+    info("NodeAgbotTokenValidation.isValid(\"ABCDEFGHIJKLMNO1\")"+ " , " + NodeAgbotTokenValidation.isValid("ABCDEFGHIJKLMNO1").toString())
+    assert(NodeAgbotTokenValidation.isValid("ABCDEFGHIJKLMNO1") == false)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies valid password"){
+    info("NodeAgbotTokenValidation.isValid(\"AAAAAAAAAAAAaB1\")"+ " , " + NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAaB1").toString())
+    assert(NodeAgbotTokenValidation.isValid("AAAAAAAAAAAAaB1") == true)
+    info("NodeAgbotTokenValidation.isValid(\"ValidPassword1!\")"+ " , " + NodeAgbotTokenValidation.isValid("ValidPassword1!").toString())
+     assert(NodeAgbotTokenValidation.isValid("ValidPassword1!") == true)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies valid password with digits only") {
+    info("NodeAgbotTokenValidation.isValid(\"123456789012345\")"+ " , " + NodeAgbotTokenValidation.isValid("123456789012345").toString())
+    assert(NodeAgbotTokenValidation.isValid("123456789012345") == false)
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies password with exactly 15 characters") {
+    info("NodeAgbotTokenValidation.isValid(\"Aa1aaaaaaaaaaaa\")"+ " , " + NodeAgbotTokenValidation.isValid("Aa1aaaaaaaaaaaa").toString())
+    assert(NodeAgbotTokenValidation.isValid("Aa1" + "a" * 12) == true)  // valid
+    info("NodeAgbotTokenValidation.isValid(\"Aaaaaaaabbbbbbb\")"+ " , " + NodeAgbotTokenValidation.isValid("Aaaaaaaabbbbbbb").toString())
+    assert(NodeAgbotTokenValidation.isValid("Aaaaaaaabbbbbbb") == false) // invalid
+    info("NodeAgbotTokenValidation.isValid(\"A1abbbbbbbbbbbb\")"+ " , " + NodeAgbotTokenValidation.isValid("A1abbbbbbbbbbbb").toString())
+    assert(NodeAgbotTokenValidation.isValid("A1a" + "b" * 12) == true)  // valid
+  }
+
+  test("NodeAgbotTokenValidation.isValid correctly identifies password with special characters") {
+    info("NodeAgbotTokenValidation.isValid(\"A1!abbbbbbbbbbb\")"+ " , " + NodeAgbotTokenValidation.isValid("A1!abbbbbbbbbbb").toString())
+    assert(NodeAgbotTokenValidation.isValid("A1!a" + "b" * 11) == true)
+    info("NodeAgbotTokenValidation.isValid(\"!A1abbbbbbbbbbb\")"+ " , " + NodeAgbotTokenValidation.isValid("!A1abbbbbbbbbbb").toString())
+    assert(NodeAgbotTokenValidation.isValid("!A1a" + "b" * 11) == true)
+  }
+}