[Dashboard] Fix timezone_utils to deal with daylight savings

The `Dashboard Server Timezone` is currently incorrect in when
running in a timezone with daylight savings. Fixing that
resolution with python `tzlocal`.

Signed-off-by: Brendan Miller <6900229+bhmiller@users.noreply.github.com>

Author: bhmiller

python/ray/dashboard/optional_deps.py

@@ -7,6 +7,7 @@
 import aiohttp.web  # noqa: F401
 import aiohttp_cors  # noqa: F401
 import grpc  # noqa: F401
+import tzlocal  # noqa: F401
 
 # These checks have to come first because aiohttp looks
 # for opencensus, too, and raises a different error otherwise.

python/ray/dashboard/timezone_utils.py

@@ -1,43 +1,5 @@
-import logging
 from datetime import datetime
-
-logger = logging.getLogger(__name__)
-
-timezones = [
-    {"offset": "-12:00", "value": "Etc/+12"},
-    {"offset": "-11:00", "value": "Pacific/Pago_Pago"},
-    {"offset": "-10:00", "value": "Pacific/Honolulu"},
-    {"offset": "-09:00", "value": "America/Anchorage"},
-    {"offset": "-08:00", "value": "America/Los_Angeles"},
-    {"offset": "-07:00", "value": "America/Phoenix"},
-    {"offset": "-06:00", "value": "America/Guatemala"},
-    {"offset": "-05:00", "value": "America/Bogota"},
-    {"offset": "-04:00", "value": "America/Halifax"},
-    {"offset": "-03:30", "value": "America/St_Johns"},
-    {"offset": "-03:00", "value": "America/Sao_Paulo"},
-    {"offset": "-02:00", "value": "America/Godthab"},
-    {"offset": "-01:00", "value": "Atlantic/Azores"},
-    {"offset": "+00:00", "value": "Europe/London"},
-    {"offset": "+01:00", "value": "Europe/Amsterdam"},
-    {"offset": "+02:00", "value": "Asia/Amman"},
-    {"offset": "+03:00", "value": "Asia/Baghdad"},
-    {"offset": "+03:30", "value": "Asia/Tehran"},
-    {"offset": "+04:00", "value": "Asia/Dubai"},
-    {"offset": "+04:30", "value": "Asia/Kabul"},
-    {"offset": "+05:00", "value": "Asia/Karachi"},
-    {"offset": "+05:30", "value": "Asia/Kolkata"},
-    {"offset": "+05:45", "value": "Asia/Kathmandu"},
-    {"offset": "+06:00", "value": "Asia/Almaty"},
-    {"offset": "+06:30", "value": "Asia/Yangon"},
-    {"offset": "+07:00", "value": "Asia/Bangkok"},
-    {"offset": "+08:00", "value": "Asia/Shanghai"},
-    {"offset": "+09:00", "value": "Asia/Irkutsk"},
-    {"offset": "+09:30", "value": "Australia/Adelaide"},
-    {"offset": "+10:00", "value": "Australia/Brisbane"},
-    {"offset": "+11:00", "value": "Asia/Magadan"},
-    {"offset": "+12:00", "value": "Pacific/Auckland"},
-    {"offset": "+13:00", "value": "Pacific/Tongatapu"},
-]
+import tzlocal
 
 
 def get_current_timezone_info():
@@ -48,9 +10,6 @@ def get_current_timezone_info():
     sign = "+" if hours >= 0 else "-"
     current_offset = f"{sign}{abs(int(hours)):02d}:{abs(int(minutes)):02d}"
 
-    current_timezone = next(
-        (tz for tz in timezones if tz["offset"] == current_offset),
-        {"offset": None, "value": None},
-    )
+    current_timezone = {"offset": current_offset, "value": tzlocal.get_localzone_name()}
 
     return current_timezone