diff --git a/sign/src/main/java/com/itextpdf/signatures/SignUtils.java b/sign/src/main/java/com/itextpdf/signatures/SignUtils.java
index 6788cef0f5..db006a6557 100644
--- a/sign/src/main/java/com/itextpdf/signatures/SignUtils.java
+++ b/sign/src/main/java/com/itextpdf/signatures/SignUtils.java
@@ -270,7 +270,9 @@ static X509Principal getIssuerX509Name(ASN1Sequence issuerAndSerialNumber) throw
     }
 
     public static String dateToString(Calendar signDate) {
-        return new SimpleDateFormat("yyyy.MM.dd HH:mm:ss z").format(signDate.getTime());
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss z");
+        if(signDate.getTimeZone() != null) sdf.setTimeZone(signDate.getTimeZone());
+        return sdf.format(signDate.getTime());
     }
 
     static class TsaResponse {