diff --git a/socketserver/server/commands.go b/socketserver/server/commands.go
index 4dcebd2d..d9df3fd2 100644
--- a/socketserver/server/commands.go
+++ b/socketserver/server/commands.go
@@ -84,6 +84,8 @@ func callHandler(handler CommandHandler, conn *websocket.Conn, client *ClientInf
 	return handler(conn, client, cmsg)
 }
 
+var lastVersionWithoutReplyWithServerTime = VersionFromString("ffz_3.5.78")
+
 // C2SHello implements the `hello` C2S Command.
 // It calls SubscribeGlobal() and SubscribeDefaults() with the client, and fills out ClientInfo.Version and ClientInfo.ClientID.
 func C2SHello(conn *websocket.Conn, client *ClientInfo, msg ClientMessage) (rmsg ClientMessage, err error) {
@@ -92,7 +94,9 @@ func C2SHello(conn *websocket.Conn, client *ClientInfo, msg ClientMessage) (rmsg
 		return
 	}
 
-	client.Version = version
+	client.VersionString = version
+	client.Version = VersionFromString(version)
+
 	client.ClientID = uuid.FromStringOrNil(clientID)
 	if client.ClientID == uuid.Nil {
 		client.ClientID = uuid.NewV4()
@@ -101,9 +105,18 @@ func C2SHello(conn *websocket.Conn, client *ClientInfo, msg ClientMessage) (rmsg
 	SubscribeGlobal(client)
 	SubscribeDefaults(client)
 
-	return ClientMessage{
-		Arguments: client.ClientID.String(),
-	}, nil
+	if client.Version.After(lastVersionWithoutReplyWithServerTime) {
+		return ClientMessage{
+			Arguments: []interface{}{
+				client.ClientID.String(),
+				time.Now().Unix(),
+			},
+		}
+	} else {
+		return ClientMessage{
+			Arguments: client.ClientID.String(),
+		}, nil
+	}
 }
 
 func C2SReady(conn *websocket.Conn, client *ClientInfo, msg ClientMessage) (rmsg ClientMessage, err error) {
diff --git a/socketserver/server/handlecore.go b/socketserver/server/handlecore.go
index fd3c8c6f..4157a8fa 100644
--- a/socketserver/server/handlecore.go
+++ b/socketserver/server/handlecore.go
@@ -261,7 +261,7 @@ RunLoop:
 			break RunLoop
 
 		case msg := <-clientChan:
-			if client.Version == "" && msg.Command != HelloCommand {
+			if client.VersionString == "" && msg.Command != HelloCommand {
 				CloseConnection(conn, &CloseFirstMessageNotHello)
 				Statistics.FirstNotHelloDisconnects++
 				break RunLoop
diff --git a/socketserver/server/types.go b/socketserver/server/types.go
index 7a3b2f99..8dbf5ca2 100644
--- a/socketserver/server/types.go
+++ b/socketserver/server/types.go
@@ -6,6 +6,7 @@ import (
 	"net"
 	"sync"
 	"time"
+	"fmt"
 )
 
 const CryptoBoxKeyLength = 32
@@ -55,14 +56,22 @@ type AuthInfo struct {
 	UsernameValidated bool
 }
 
+type ClientVersion struct {
+	Major int
+	Minor int
+	Revision int
+}
+
 type ClientInfo struct {
 	// The client ID.
 	// This must be written once by the owning goroutine before the struct is passed off to any other goroutines.
 	ClientID uuid.UUID
 
-	// The client's version.
+	// The client's literal version string.
 	// This must be written once by the owning goroutine before the struct is passed off to any other goroutines.
-	Version string
+	VersionString string
+
+	Version ClientVersion
 
 	// This mutex protects writable data in this struct.
 	// If it seems to be a performance problem, we can split this.
@@ -103,6 +112,36 @@ type ClientInfo struct {
 	pingCount int
 }
 
+func VersionFromString(v string) ClientVersion {
+	var cv ClientVersion
+	fmt.Sscanf(v, "ffz_%d.%d.%d", &cv.Major, &cv.Minor, &cv.Revision)
+	return cv
+}
+
+func (cv *ClientVersion) After(cv2 *ClientVersion) bool {
+	if cv.Major > cv2.Major {
+		return true
+	} else if cv.Major < cv2.Major {
+		return false
+	}
+	if cv.Minor > cv2.Minor {
+		return true
+	} else if cv.Minor < cv2.Minor {
+		return false
+	}
+	if cv.Revision > cv2.Revision {
+		return true
+	} else if cv.Revision < cv2.Revision {
+		return false
+	}
+
+	return false // equal
+}
+
+func (cv *ClientVersion) Equal(cv2 *ClientVersion) bool {
+	return cv.Major == cv2.Major && cv.Minor == cv2.Minor && cv.Revision == cv2.Revision
+}
+
 const usePendingSubscrptionsBacklog = false
 
 type tgmarray []TimestampedGlobalMessage