diff --git a/client/cmd/saveHistoryEntry.go b/client/cmd/saveHistoryEntry.go
index aa90160..fe3db68 100644
--- a/client/cmd/saveHistoryEntry.go
+++ b/client/cmd/saveHistoryEntry.go
@@ -152,9 +152,7 @@ func presaveHistoryEntry(ctx context.Context) {
 		// Don't save commands that start with a space
 		return
 	}
-	startTime, err := parseCrossPlatformInt(os.Args[4])
-	lib.CheckFatalError(err)
-	entry.StartTime = time.Unix(startTime, 0).UTC()
+	entry.StartTime = parseCrossPlatformTime(os.Args[4])
 	entry.EndTime = time.Unix(0, 0).UTC()
 
 	// And persist it locally.
@@ -369,11 +367,7 @@ func buildHistoryEntry(ctx context.Context, args []string) (*data.HistoryEntry,
 	entry.ExitCode = exitCode
 
 	// start time
-	seconds, err := parseCrossPlatformInt(args[5])
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse start time %s as int: %w", args[5], err)
-	}
-	entry.StartTime = time.Unix(seconds, 0).UTC()
+	entry.StartTime = parseCrossPlatformTime(args[5])
 
 	// end time
 	entry.EndTime = time.Now().UTC()
@@ -549,9 +543,16 @@ func maybeSkipBashHistTimePrefix(cmdLine string) (string, error) {
 	return re.ReplaceAllLiteralString(cmdLine, ""), nil
 }
 
-func parseCrossPlatformInt(data string) (int64, error) {
-	data = strings.TrimSuffix(data, "N")
-	return strconv.ParseInt(data, 10, 64)
+func parseCrossPlatformTime(data string) time.Time {
+	data = strings.TrimSuffix(data, "N") // Trim the N suffix that is present on MacOS where the date CLI doesn't support %N
+	startTime, err := strconv.ParseInt(data, 10, 64)
+	lib.CheckFatalError(err)
+	if len(data) >= 18 {
+		return time.Unix(0, startTime).UTC()
+	} else {
+		return time.Unix(startTime, 0).UTC()
+	}
+
 }
 
 func getLastCommand(history string) (string, error) {
diff --git a/client/cmd/saveHistoryEntry_test.go b/client/cmd/saveHistoryEntry_test.go
index 5d92648..bb82744 100644
--- a/client/cmd/saveHistoryEntry_test.go
+++ b/client/cmd/saveHistoryEntry_test.go
@@ -135,17 +135,18 @@ func TestBuildHistoryEntryWithTimestampStripping(t *testing.T) {
 	}
 }
 
-func TestParseCrossPlatformInt(t *testing.T) {
-	res, err := parseCrossPlatformInt("123")
-	require.NoError(t, err)
-	if res != 123 {
-		t.Fatalf("failed to parse cross platform int %d", res)
-	}
-	res, err = parseCrossPlatformInt("123N")
-	require.NoError(t, err)
-	if res != 123 {
-		t.Fatalf("failed to parse cross platform int %d", res)
-	}
+func TestParseCrossPlatformTime(t *testing.T) {
+	res := parseCrossPlatformTime("1696715149")
+	require.Equal(t, time.Unix(1696715149, 0).UTC(), res)
+
+	res = parseCrossPlatformTime("1696715149N")
+	require.Equal(t, time.Unix(1696715149, 0).UTC(), res)
+
+	res = parseCrossPlatformTime("1696715218277655463")
+	require.Equal(t, time.Unix(0, 1696715218277655463).UTC(), res)
+
+	res = parseCrossPlatformTime("1696715218277655463N")
+	require.Equal(t, time.Unix(0, 1696715218277655463).UTC(), res)
 }
 
 func TestBuildRegexFromTimeFormat(t *testing.T) {
diff --git a/client/lib/config.fish b/client/lib/config.fish
index 0cb0d78..08205fc 100644
--- a/client/lib/config.fish
+++ b/client/lib/config.fish
@@ -1,7 +1,7 @@
 function _hishtory_post_exec --on-event fish_preexec 
     # Runs after <ENTER>, but before the command is executed
     set --global _hishtory_command $argv
-    set --global _hishtory_start_time (date +%s)
+    set --global _hishtory_start_time (date +%s%N)
     hishtory presaveHistoryEntry fish "$_hishtory_command" $_hishtory_start_time & # Background Run
     # hishtory presaveHistoryEntry fish "$_hishtory_command" $_hishtory_start_time # Foreground Run
 end
diff --git a/client/lib/config.sh b/client/lib/config.sh
index 7005ecd..f1d253e 100644
--- a/client/lib/config.sh
+++ b/client/lib/config.sh
@@ -13,7 +13,7 @@ function __hishtory_precommand() {
   unset HISHTORY_AT_PROMPT
 
   # Run before every command
-  HISHTORY_START_TIME=`date +%s`
+  HISHTORY_START_TIME=`date +%s%N`
   CMD=`history 1`
   if ! [ -z "CMD " ] ; then
     (hishtory presaveHistoryEntry bash "$CMD" $HISHTORY_START_TIME &) # Background Run
diff --git a/client/lib/config.zsh b/client/lib/config.zsh
index 346e7eb..fc2e498 100644
--- a/client/lib/config.zsh
+++ b/client/lib/config.zsh
@@ -8,7 +8,7 @@ function _hishtory_add() {
     # Runs after <ENTER>, but before the command is executed
     # $1 contains the command that was run 
     _hishtory_command=$1
-    _hishtory_start_time=`date +%s`
+    _hishtory_start_time=`date +%s%N`
     if ! [ -z "$_hishtory_command " ]; then
         (hishtory presaveHistoryEntry zsh "$_hishtory_command" $_hishtory_start_time &)  # Background Run
         # hishtory presaveHistoryEntry zsh "$_hishtory_command" $_hishtory_start_time  # Foreground Run