fix date formatting

src/agentx-ntpsec.py

@@ -1,4 +1,5 @@
 import ntp.packet
+import ntp.ntpc
 import threading
 from contextlib import AbstractContextManager
 import time
@@ -40,14 +41,7 @@ def pass_value(x):
     return x
 
 def string_ntp_seconds(x):
-    h1, h2 = x.split('.')
-    seconds = int(h1, 16)
-    fraction = int(h2, 16)
-    ntp_epoch = datetime.datetime(1900, 1, 1)
-    timestamp = ntp_epoch + datetime.timedelta(seconds=seconds)
-    microseconds = fraction // 1000
-    timestamp = timestamp.replace(microsecond=microseconds)
-    return f"{timestamp} UTC"
+    return ntp.ntpc.prettydate(x).split(' ')[1]
 
 
 SYSINFO_KEYS = [