use rfc3339 format for log time stamps (#4384)

core/dbt/events/base_types.py

@@ -75,6 +75,7 @@ class Event(metaclass=ABCMeta):
     # fields that should be on all events with their default implementations
     log_version: int = 1
     ts: Optional[datetime] = None  # use getter for non-optional
+    ts_rfc3339: Optional[str] = None  # use getter for non-optional
     pid: Optional[int] = None  # use getter for non-optional
     node_info: Optional[Node]
 
@@ -119,9 +120,17 @@ def fields_to_json(self, field_value: Any) -> Any:
     # exactly one time stamp per concrete event
     def get_ts(self) -> datetime:
         if not self.ts:
-            self.ts = datetime.now()
+            self.ts = datetime.utcnow()
+            self.ts_rfc3339 = self.ts.strftime('%Y-%m-%dT%H:%M:%S.%fZ')
         return self.ts
 
+    # preformatted time stamp
+    def get_ts_rfc3339(self) -> str:
+        if not self.ts_rfc3339:
+            # get_ts() creates the formatted string too so all time logic is centralized
+            self.get_ts()
+        return self.ts_rfc3339  # type: ignore
+
     # exactly one pid per concrete event
     def get_pid(self) -> int:
         if not self.pid:

core/dbt/events/functions.py

@@ -174,7 +174,8 @@ def create_text_log_line(e: T_Event, msg_fn: Callable[[T_Event], str]) -> str:
 # translates an Event to a completely formatted json log line
 # you have to specify which message you want. (i.e. - e.message(), e.cli_msg(), e.file_msg())
 def create_json_log_line(e: T_Event, msg_fn: Callable[[T_Event], str]) -> str:
-    values = event_to_serializable_dict(e, lambda dt: dt.isoformat(), lambda x: msg_fn(x))
+    # using preformatted string instead of formatting it here to be extra careful about timezone
+    values = event_to_serializable_dict(e, lambda _: e.get_ts_rfc3339(), lambda x: msg_fn(x))
     raw_log_line = json.dumps(values, sort_keys=True)
     return scrub_secrets(raw_log_line, env_secrets())