diff --git a/log/event.go b/log/event.go
index 775159b5..ccde4126 100644
--- a/log/event.go
+++ b/log/event.go
@@ -3,6 +3,7 @@ package log
 import (
 	"encoding/json"
 	"fmt"
+	"heckel.io/ntfy/util"
 	"log"
 	"os"
 	"sort"
@@ -11,12 +12,11 @@ import (
 )
 
 const (
-	fieldTag        = "tag"
-	fieldError      = "error"
-	fieldTimeTaken  = "time_taken_ms"
-	fieldExitCode   = "exit_code"
-	tagStdLog       = "stdlog"
-	timestampFormat = "2006-01-02T15:04:05.999Z07:00"
+	fieldTag       = "tag"
+	fieldError     = "error"
+	fieldTimeTaken = "time_taken_ms"
+	fieldExitCode  = "exit_code"
+	tagStdLog      = "stdlog"
 )
 
 // Event represents a single log event
@@ -143,7 +143,7 @@ func (e *Event) Render(l Level, message string, v ...any) string {
 	}
 	e.Message = fmt.Sprintf(message, v...)
 	e.Level = l
-	e.Timestamp = e.time.Format(timestampFormat)
+	e.Timestamp = util.FormatTime(e.time)
 	if !appliedContexters {
 		e.applyContexters()
 	}
diff --git a/server/visitor.go b/server/visitor.go
index 80bac46f..63a3ac60 100644
--- a/server/visitor.go
+++ b/server/visitor.go
@@ -143,6 +143,7 @@ func (v *visitor) contextNoLock() log.Context {
 	fields := log.Context{
 		"visitor_id":                     visitorID(v.ip, v.user),
 		"visitor_ip":                     v.ip.String(),
+		"visitor_seen":                   util.FormatTime(v.seen),
 		"visitor_messages":               info.Stats.Messages,
 		"visitor_messages_limit":         info.Limits.MessageLimit,
 		"visitor_messages_remaining":     info.Stats.MessagesRemaining,
diff --git a/util/time.go b/util/time.go
index 1a455770..14aa3936 100644
--- a/util/time.go
+++ b/util/time.go
@@ -14,6 +14,15 @@ var (
 	durationStrRegex  = regexp.MustCompile(`(?i)^(\d+)\s*(d|days?|h|hours?|m|mins?|minutes?|s|secs?|seconds?)$`)
 )
 
+const (
+	timestampFormat = "2006-01-02T15:04:05.999Z07:00" // Like RFC3339, but with milliseconds
+)
+
+// FormatTime formats a time.Time in a RFC339-like format that includes milliseconds
+func FormatTime(t time.Time) string {
+	return t.Format(timestampFormat)
+}
+
 // NextOccurrenceUTC takes a time of day (e.g. 9:00am), and returns the next occurrence
 // of that time from the current time (in UTC).
 func NextOccurrenceUTC(timeOfDay, base time.Time) time.Time {