diff --git a/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Mcp23xxx/Driver/Mcp23xxx.DigitalInterruptPort.cs b/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Mcp23xxx/Driver/Mcp23xxx.DigitalInterruptPort.cs
index ec1ecc7565..621b62be21 100644
--- a/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Mcp23xxx/Driver/Mcp23xxx.DigitalInterruptPort.cs
+++ b/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Mcp23xxx/Driver/Mcp23xxx.DigitalInterruptPort.cs
@@ -14,7 +14,7 @@ public class DigitalInterruptPort : DigitalInterruptPortBase
             public override bool State => state;
             private bool state = false;
 
-            private DateTime lastUpdate;
+            private int lastUpdate;
 
             /// <inheritdoc/>
             public override ResistorMode Resistor
@@ -52,13 +52,13 @@ public DigitalInterruptPort(IPin pin, InterruptMode interruptMode = InterruptMod
             /// <param name="newState">The new port state</param>
             internal void Update(bool newState)
             {
-                if (DateTime.UtcNow - lastUpdate < DebounceDuration)
+                var now = Environment.TickCount;
+
+                if (now - lastUpdate < DebounceDuration.TotalMilliseconds)
                 {
                     return;
                 }
 
-                var now = DateTime.UtcNow;
-
                 if (newState != state)
                 {
                     switch (InterruptMode)
diff --git a/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Pcx857x/Driver/Pcx857x.DigitalInterruptPort.cs b/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Pcx857x/Driver/Pcx857x.DigitalInterruptPort.cs
index 1f56366e13..7d839648b1 100644
--- a/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Pcx857x/Driver/Pcx857x.DigitalInterruptPort.cs
+++ b/Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Pcx857x/Driver/Pcx857x.DigitalInterruptPort.cs
@@ -30,7 +30,7 @@ public override ResistorMode Resistor
             public override bool State => state;
             private bool state = false;
 
-            private DateTime lastUpdate;
+            private int lastUpdate;
 
             private ResistorMode resistorMode = ResistorMode.Disabled;
 
@@ -68,13 +68,13 @@ public DigitalInterruptPort(IPin pin, InterruptMode interruptMode = InterruptMod
             /// <param name="newState">The new port state</param>
             internal void Update(bool newState)
             {
-                if (DateTime.UtcNow - lastUpdate < DebounceDuration)
+                var now = Environment.TickCount;
+
+                if (now - lastUpdate < DebounceDuration.TotalMilliseconds)
                 {
                     return;
                 }
 
-                var now = DateTime.UtcNow;
-
                 if (newState != state)
                 {
                     switch (InterruptMode)
diff --git a/Source/Meadow.Foundation.Peripherals/Sensors.Hid.Keyboard/Driver/Keyboard.KeyboardKey.cs b/Source/Meadow.Foundation.Peripherals/Sensors.Hid.Keyboard/Driver/Keyboard.KeyboardKey.cs
index 43afbe3828..8f55749296 100644
--- a/Source/Meadow.Foundation.Peripherals/Sensors.Hid.Keyboard/Driver/Keyboard.KeyboardKey.cs
+++ b/Source/Meadow.Foundation.Peripherals/Sensors.Hid.Keyboard/Driver/Keyboard.KeyboardKey.cs
@@ -45,17 +45,17 @@ internal void SetState(bool newState)
                     case InterruptMode.EdgeRising:
                         if (State)
                         {
-                            RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, DateTime.UtcNow), null));
+                            RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, Environment.TickCount), null));
                         }
                         break;
                     case InterruptMode.EdgeFalling:
                         if (!State)
                         {
-                            RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, DateTime.UtcNow), null));
+                            RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, Environment.TickCount), null));
                         }
                         break;
                     case InterruptMode.EdgeBoth:
-                        RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, DateTime.UtcNow), null));
+                        RaiseChangedAndNotify(new DigitalPortResult(new DigitalState(State, Environment.TickCount), null));
                         break;
                 }
             }
diff --git a/Source/Meadow.Foundation.Peripherals/Sensors.Weather.SwitchingAnemometer/Driver/SwitchingAnemometer.cs b/Source/Meadow.Foundation.Peripherals/Sensors.Weather.SwitchingAnemometer/Driver/SwitchingAnemometer.cs
index 4ca8c780ab..4534cf2627 100644
--- a/Source/Meadow.Foundation.Peripherals/Sensors.Weather.SwitchingAnemometer/Driver/SwitchingAnemometer.cs
+++ b/Source/Meadow.Foundation.Peripherals/Sensors.Weather.SwitchingAnemometer/Driver/SwitchingAnemometer.cs
@@ -63,7 +63,7 @@ public int SampleCount
         /// <summary>
         /// Did we create the port(s) used by the peripheral
         /// </summary>
-        readonly bool createdPort = false;
+        private readonly bool createdPort = false;
 
         /// <summary>
         /// Creates a new `SwitchingAnemometer` using the specific digital input
@@ -152,7 +152,9 @@ protected override async Task<Speed> ReadSensor()
                 StopUpdating();
             }
 
-            if (samples?.Count > 0 && (DateTime.UtcNow - samples?.Peek().New.Time > NoWindTimeout))
+            var now = Environment.TickCount;
+
+            if (samples?.Count > 0 && (TimeSpan.FromMilliseconds(now - samples?.Peek().New.Time ?? 0) > NoWindTimeout))
             {   //we've exceeded the no wind interval time 
                 samples?.Clear(); //will force a zero reading
             }
@@ -166,7 +168,7 @@ protected override async Task<Speed> ReadSensor()
                 {   // skip the first (old will be null)
                     if (sample.Old is { } old)
                     {
-                        speedSum += SwitchIntervalToKmh(sample.New.Time - old.Time);
+                        speedSum += SwitchIntervalToKmh(TimeSpan.FromMilliseconds(sample.New.Time - old.Time));
                     }
                 }