diff --git a/modules/activitypub/client.go b/modules/activitypub/client.go
index 2e872d2dbe..bcd248e21a 100644
--- a/modules/activitypub/client.go
+++ b/modules/activitypub/client.go
@@ -11,6 +11,7 @@ import (
 	"encoding/pem"
 	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	user_model "code.gitea.io/gitea/models/user"
@@ -106,7 +107,7 @@ func (c *Client) NewRequest(b []byte, to string) (req *http.Request, err error)
 	}
 	req.Header.Add("Content-Type", ActivityStreamsContentType)
 	req.Header.Add("Accept-Charset", "utf-8")
-	req.Header.Add("Date", fmt.Sprintf("%s UTC", time.Now().UTC().Format(time.RFC1123)))
+	req.Header.Add("Date", strings.ReplaceAll(time.Now().UTC().Format(time.RFC1123), "UTC", "GMT"))
 
 	signer, _, err := httpsig.NewSigner(c.algs, c.digestAlg, c.postHeaders, httpsig.Signature, httpsigExpirationTime)
 	if err != nil {
diff --git a/routers/api/v1/activitypub/person.go b/routers/api/v1/activitypub/person.go
index 22f00c01e0..bb3b2b23e3 100644
--- a/routers/api/v1/activitypub/person.go
+++ b/routers/api/v1/activitypub/person.go
@@ -56,13 +56,13 @@ func Person(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "Set PreferredUsername", err)
 		return
 	}
-	
+
 	person.URL = ap.IRI(setting.AppURL + username)
 
 	person.Icon = ap.Image{
-		Type: ap.ImageType,
+		Type:      ap.ImageType,
 		MediaType: "image/png",
-		URL: ap.IRI(user.AvatarLink()),
+		URL:       ap.IRI(user.AvatarLink()),
 	}
 
 	person.Inbox = nil
@@ -91,12 +91,12 @@ func Person(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "Unmarshall", err)
 	}
 
-	jsonmap["@context"] = []string{"https://www.w3.org/ns/activitystreams", "https://w3id.org/security/v1"} 
+	jsonmap["@context"] = []string{"https://www.w3.org/ns/activitystreams", "https://w3id.org/security/v1"}
 
 	ctx.Resp.Header().Add("Content-Type", "application/activity+json")
 	ctx.Resp.WriteHeader(http.StatusOK)
 	binary, _ = json.Marshal(jsonmap)
-	ctx.Resp.Write(binary)
+	_, _ = ctx.Resp.Write(binary)
 }
 
 // PersonInbox function
diff --git a/routers/api/v1/activitypub/reqsignature.go b/routers/api/v1/activitypub/reqsignature.go
index 906be714da..ffc69aa8de 100644
--- a/routers/api/v1/activitypub/reqsignature.go
+++ b/routers/api/v1/activitypub/reqsignature.go
@@ -13,6 +13,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"strings"
 	"time"
 
 	"code.gitea.io/gitea/modules/activitypub"
@@ -50,7 +51,7 @@ func fetch(iri *url.URL) (b []byte, err error) {
 	req := httplib.NewRequest(iri.String(), http.MethodGet)
 	req.Header("Accept", activitypub.ActivityStreamsContentType)
 	req.Header("Accept-Charset", "utf-8")
-	req.Header("Date", fmt.Sprintf("%s UTC", time.Now().UTC().Format(time.RFC1123)))
+	req.Header("Date", strings.ReplaceAll(time.Now().UTC().Format(time.RFC1123), "UTC", "GMT"))
 	resp, err := req.Response()
 	if err != nil {
 		return