diff --git a/trezor_agent/gpg/encode.py b/trezor_agent/gpg/encode.py
index 6c9cb18..aace88c 100644
--- a/trezor_agent/gpg/encode.py
+++ b/trezor_agent/gpg/encode.py
@@ -1,7 +1,6 @@
 """Create GPG ECDSA signatures and public keys using TREZOR device."""
 import io
 import logging
-import time
 
 from . import decode, keyring, protocol
 from .. import util
@@ -9,10 +8,6 @@ from .. import util
 log = logging.getLogger(__name__)
 
 
-def _time_format(t):
-    return time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(t))
-
-
 def create_primary(user_id, pubkey, signer_func):
     """Export new primary GPG public key, ready for "gpg2 --import"."""
     pubkey_packet = protocol.packet(tag=6, blob=pubkey.data())