PR feedback, test zero

Author: tedder

adafruit_ntp.py

@@ -103,13 +103,8 @@ def datetime(self) -> time.struct_time:
             seconds = struct.unpack_from("!I", self._packet, offset=PACKET_SIZE - 8)[0]
 
             # value should always be larger; giving a small buffer to handle jitter.
-            if (seconds + 5) < self._monotonic_start:
-                failed_offset = (self._monotonic_start - seconds) / 1_000_000_000
-                raise ArithmeticError(
-                    "need a time machine, ntp time is "
-                    + str(failed_offset)
-                    + "seconds in the past."
-                )
+            if seconds == 0:
+                raise ArithmeticError("ntp value is invalid (empty)")
 
             self._monotonic_start = (
                 seconds