Remove unused code & tidy

Author: MetRonnie

cylc/flow/wallclock.py

@@ -43,7 +43,6 @@
 TIME_ZONE_STRING_LOCAL_EXTENDED = get_local_time_zone_format(
     TimeZoneFormatMode.extended)
 TIME_ZONE_STRING_UTC = "Z"
-TIME_ZONE_UTC_UTC_OFFSET = (0, 0)
 TIME_ZONE_LOCAL_UTC_OFFSET = get_local_time_zone()
 
 TIME_ZONE_LOCAL_INFO = {
@@ -54,8 +53,8 @@
 }
 
 TIME_ZONE_UTC_INFO = {
-    "hours": TIME_ZONE_UTC_UTC_OFFSET[0],
-    "minutes": TIME_ZONE_UTC_UTC_OFFSET[1],
+    "hours": 0,
+    "minutes": 0,
     "string_basic": TIME_ZONE_STRING_UTC,
     "string_extended": TIME_ZONE_STRING_UTC
 }
@@ -113,9 +112,13 @@ def get_current_time_string(display_sub_seconds=False, override_use_utc=None,
                            use_basic_format=use_basic_format)
 
 
-def get_time_string(date_time, display_sub_seconds=False,
-                    override_use_utc=None, use_basic_format=False,
-                    date_time_is_local=False, custom_time_zone_info=None):
+def get_time_string(
+    date_time: datetime,
+    display_sub_seconds: bool = False,
+    override_use_utc: Optional[bool] = None,
+    use_basic_format: bool = False,
+    date_time_is_local: bool = False,
+):
     """Return a string representing the current system time.
 
     Arguments:
@@ -133,31 +136,10 @@ def get_time_string(date_time, display_sub_seconds=False,
     most useful for filenames where ":" may cause problems.
     date_time_is_local - a boolean that, if True, indicates that
     the date_time argument object is in the local time zone, not UTC.
-    custom_time_zone_info (default None) - a dictionary that enforces
-    a particular time zone. It looks like {"hours": _hours,
-    "minutes": _minutes, "string": _string} where _hours and _minutes
-    are the hours and minutes offset from UTC and _string is the string
-    to use as the time zone designator.
 
     """
     time_zone_string = None
-    if custom_time_zone_info is not None:
-        custom_hours = custom_time_zone_info["hours"]
-        custom_minutes = custom_time_zone_info["minutes"]
-        if use_basic_format:
-            custom_string = custom_time_zone_info["string_basic"]
-        else:
-            custom_string = custom_time_zone_info["string_extended"]
-        if date_time_is_local:
-            date_time_hours, date_time_minutes = TIME_ZONE_LOCAL_UTC_OFFSET
-        else:
-            date_time_hours, date_time_minutes = (0, 0)
-        diff_hours = custom_hours - date_time_hours
-        diff_minutes = custom_minutes - date_time_minutes
-        date_time = date_time + timedelta(
-            hours=diff_hours, minutes=diff_minutes)
-        time_zone_string = custom_string
-    elif override_use_utc or (override_use_utc is None and _FLAGS['utc_mode']):
+    if override_use_utc or (override_use_utc is None and _FLAGS['utc_mode']):
         time_zone_string = TIME_ZONE_STRING_UTC
         if date_time_is_local:
             h, m = TIME_ZONE_LOCAL_UTC_OFFSET
@@ -183,9 +165,11 @@ def get_time_string(date_time, display_sub_seconds=False,
     return date_time_string + time_zone_string
 
 
-def get_time_string_from_unix_time(unix_time, display_sub_seconds=False,
-                                   use_basic_format=False,
-                                   custom_time_zone_info=None):
+def get_time_string_from_unix_time(
+    unix_time: float,
+    display_sub_seconds: bool = False,
+    use_basic_format: bool = False,
+) -> str:
     """Convert a unix timestamp into a local time zone datetime.datetime.
 
     Arguments:
@@ -198,20 +182,15 @@ def get_time_string_from_unix_time(unix_time, display_sub_seconds=False,
     use_basic_format (default False) - a boolean that, if True,
     represents the date/time without "-" or ":" delimiters. This is
     most useful for filenames where ":" may cause problems.
-    custom_time_zone_info (default None) - a dictionary that enforces
-    a particular time zone. It looks like {"hours": _hours,
-    "minutes": _minutes, "string": _string} where _hours and _minutes
-    are the hours and minutes offset from UTC and _string is the string
-    to use as the time zone designator.
 
     """
-    date_time = datetime.fromtimestamp(unix_time, timezone.utc)
-    return get_time_string(date_time,
-                           display_sub_seconds=display_sub_seconds,
-                           use_basic_format=use_basic_format,
-                           override_use_utc=None,
-                           date_time_is_local=False,
-                           custom_time_zone_info=custom_time_zone_info)
+    return get_time_string(
+        datetime.fromtimestamp(unix_time, timezone.utc),
+        display_sub_seconds=display_sub_seconds,
+        use_basic_format=use_basic_format,
+        override_use_utc=None,
+        date_time_is_local=False,
+    )
 
 
 def get_unix_time_from_time_string(datetime_string):