diff --git a/runelite-client/src/main/java/net/runelite/client/plugins/timetracking/clocks/ClockPanel.java b/runelite-client/src/main/java/net/runelite/client/plugins/timetracking/clocks/ClockPanel.java
index 3b46a6c22b..b2cc8bd27f 100644
--- a/runelite-client/src/main/java/net/runelite/client/plugins/timetracking/clocks/ClockPanel.java
+++ b/runelite-client/src/main/java/net/runelite/client/plugins/timetracking/clocks/ClockPanel.java
@@ -32,6 +32,8 @@ import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
+import java.time.Duration;
+import java.time.format.DateTimeParseException;
 import javax.swing.BorderFactory;
 import javax.swing.JPanel;
 import javax.swing.SwingConstants;
@@ -52,6 +54,9 @@ abstract class ClockPanel extends JPanel
 	private static final Color ACTIVE_CLOCK_COLOR = ColorScheme.LIGHT_GRAY_COLOR.brighter();
 	private static final Color INACTIVE_CLOCK_COLOR = ColorScheme.LIGHT_GRAY_COLOR.darker();
 
+	private static final String INPUT_HMS_REGEX = ".*[hms].*";
+	private static final String WHITESPACE_REGEX = "\\s+";
+
 	// additional content or buttons should be added to these panels in the subclasses
 	final JPanel contentContainer;
 	final JPanel leftActions;
@@ -133,21 +138,38 @@ abstract class ClockPanel extends JPanel
 			@Override
 			public void focusLost(FocusEvent e)
 			{
-				String[] parts = displayInput.getText().split(":");
 				long duration = 0;
+				String text = displayInput.getText();
 
-				// parse from back to front, so as to accept hour:min:sec, min:sec, and sec formats
-				for (int i = parts.length - 1, multiplier = 1; i >= 0 && multiplier <= 3600; i--, multiplier *= 60)
+				if (text.matches(INPUT_HMS_REGEX))
 				{
+					String textWithoutWhitespaces = text.replaceAll(WHITESPACE_REGEX, "");
 					try
 					{
-						duration += Integer.parseInt(parts[i].trim()) * multiplier;
+						//parse input using ISO-8601 Duration format (e.g. 'PT1h30m10s')
+						duration = Duration.parse("PT" + textWithoutWhitespaces).toMillis() / 1000;
 					}
-					catch (NumberFormatException nfe)
+					catch (DateTimeParseException exception)
 					{
 						// ignored
 					}
 				}
+				else
+				{
+					String[] parts = text.split(":");
+					// parse from back to front, so as to accept hour:min:sec, min:sec, and sec formats
+					for (int i = parts.length - 1, multiplier = 1; i >= 0 && multiplier <= 3600; i--, multiplier *= 60)
+					{
+						try
+						{
+							duration += Integer.parseInt(parts[i].trim()) * multiplier;
+						}
+						catch (NumberFormatException nfe)
+						{
+							// ignored
+						}
+					}
+				}
 
 				clock.setDuration(Math.max(0, duration));
 				clock.reset();