diff --git a/core/internal/server/tailscale/client.go b/core/internal/server/tailscale/client.go
index 0602fc067..b3b98b480 100644
--- a/core/internal/server/tailscale/client.go
+++ b/core/internal/server/tailscale/client.go
@@ -1,7 +1,6 @@
 package tailscale
 
 import (
-	"fmt"
 	"sort"
 	"strings"
 	"time"
@@ -103,35 +102,8 @@ func convertPeerStatus(ps *ipnstate.PeerStatus, users map[tailcfg.UserID]tailcfg
 	}
 
 	if !ps.LastSeen.IsZero() {
-		peer.LastSeen = formatRelativeTime(ps.LastSeen)
+		peer.LastSeen = ps.LastSeen.UTC().Format(time.RFC3339)
 	}
 
 	return peer
 }
-
-// formatRelativeTime formats a time as a human-readable relative duration (e.g., "5 minutes ago").
-func formatRelativeTime(t time.Time) string {
-	d := time.Since(t)
-	switch {
-	case d < time.Minute:
-		return "just now"
-	case d < time.Hour:
-		m := int(d.Minutes())
-		if m == 1 {
-			return "1 minute ago"
-		}
-		return fmt.Sprintf("%d minutes ago", m)
-	case d < 24*time.Hour:
-		h := int(d.Hours())
-		if h == 1 {
-			return "1 hour ago"
-		}
-		return fmt.Sprintf("%d hours ago", h)
-	default:
-		days := int(d.Hours() / 24)
-		if days == 1 {
-			return "1 day ago"
-		}
-		return fmt.Sprintf("%d days ago", days)
-	}
-}
diff --git a/core/internal/server/tailscale/client_test.go b/core/internal/server/tailscale/client_test.go
index 0c2006bb2..3a1b19c42 100644
--- a/core/internal/server/tailscale/client_test.go
+++ b/core/internal/server/tailscale/client_test.go
@@ -169,23 +169,3 @@ func TestPeerSorting(t *testing.T) {
 	assert.Equal(t, "beta", state.Peers[1].Hostname)
 	assert.Equal(t, "zebra", state.Peers[2].Hostname)
 }
-
-func TestFormatRelativeTime(t *testing.T) {
-	tests := []struct {
-		name     string
-		duration string
-		contains string
-	}{
-		{"minutes", "5m", "minutes ago"},
-		{"hours", "3h", "hours ago"},
-		{"days", "48h", "days ago"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			d, _ := time.ParseDuration(tt.duration)
-			result := formatRelativeTime(time.Now().Add(-d))
-			assert.Contains(t, result, tt.contains)
-		})
-	}
-}
diff --git a/quickshell/Modules/ControlCenter/BuiltinPlugins/TailscaleWidget.qml b/quickshell/Modules/ControlCenter/BuiltinPlugins/TailscaleWidget.qml
index 3ba59a14e..c52e724cd 100644
--- a/quickshell/Modules/ControlCenter/BuiltinPlugins/TailscaleWidget.qml
+++ b/quickshell/Modules/ControlCenter/BuiltinPlugins/TailscaleWidget.qml
@@ -48,6 +48,17 @@ PluginComponent {
             property int filterIndex: 0
             property string expandedHostname: ""
 
+            function formatLastSeen(iso) {
+                const date = new Date(iso);
+                const minutes = Math.floor((Date.now() - date.getTime()) / 60000);
+                if (minutes < 60)
+                    return I18n.tr("%1m ago", "Tailscale peer last seen time, %1 is a number of minutes").arg(Math.max(1, minutes));
+                const hours = Math.floor(minutes / 60);
+                if (hours < 24)
+                    return I18n.tr("%1h ago", "Tailscale peer last seen time, %1 is a number of hours").arg(hours);
+                return I18n.tr("%1d ago", "Tailscale peer last seen time, %1 is a number of days").arg(Math.floor(hours / 24));
+            }
+
             readonly property string title: I18n.tr("Tailscale", "Tailscale mesh VPN widget title")
             readonly property string noneLabel: I18n.tr("None", "Tailscale exit node: none selected")
             readonly property var filteredPeers: {
@@ -207,7 +218,7 @@ PluginComponent {
                                     if (modelData.online)
                                         parts.push(modelData.relay ? I18n.tr("relay: %1", "Tailscale relay server name").arg(modelData.relay) : I18n.tr("direct", "Tailscale direct connection"));
                                     else if (modelData.lastSeen)
-                                        parts.push(I18n.tr("last seen %1", "Tailscale peer last seen time").arg(modelData.lastSeen));
+                                        parts.push(I18n.tr("last seen %1", "Tailscale peer last seen time").arg(detailRoot.formatLastSeen(modelData.lastSeen)));
                                     return parts.join(" • ");
                                 }
                                 trailingBadge: isSelf ? I18n.tr("This device", "Label for the user's own device in Tailscale") : ""