I'm encountering multiple UnknownTimezoneWarning errors when parsing dates with Python's dateutil.parser. The warnings are for various timezone abbreviations like UT, PDT, EDT, EST, PST, CEDT, EET, EEST, CES, and MET. The warning suggests using the tzinfos argument for timezone-aware datetime parsing. How can I effectively address these warnings? Is there a comprehensive tzinfos dictionary available, or should I manually map these timezones? Additionally, why does this issue arise even though I'm using libraries like pendulum, which depends on pytz?
I tried to handle these warnings by creating a tzinfos dictionary, but it's incomplete and doesn't cover all cases. Here's what I've done so far in Python:
import pendulum
# Dictionary to map timezone abbreviations to their UTC offsets
tzinfos = {
"UT": 0, "UTC": 0, "GMT": 0, # Universal Time Coordinated
"EST": -5*3600, "EDT": -4*3600, # Eastern Time
"CST": -6*3600, "CDT": -5*3600, # Central Time
"MST": -7*3600, "MDT": -6*3600, # Mountain Time
"PST": -8*3600, "PDT": -7*3600, # Pacific Time
"HST": -10*3600, "AKST": -9*3600, "AKDT": -8*3600, # Hawaii and Alaska Time
"CEDT": 2*3600, "EET": 2*3600, "EEST": 3*3600, # Central European and Eastern European Time
"CES": 1*3600, "MET": 1*3600 # Central European Summer Time and Middle European Time
}
def convert_dates_to_iso_with_pendulum(data):
for item in data:
# Parse the date using Pendulum with the tzinfos dictionary
parsed_date = pendulum.parse(item["date"], strict=False, tzinfos=tzinfos)
# Convert the date to ISO 8601 format
item["date"] = parsed_date.to_iso8601_string()
return data
This code attempts to map the known timezone abbreviations to their respective UTC offsets. I am looking for advice on improving this approach to cover more cases or handle it more effectively.
is e.g. any of
Getting a comprehensive list of timezones for my usecase of converting date strings with timezone formats to zulu based iso format was quite tricky and is not finished yet.
see also https://wiki.bitplan.com/index.php/Timezones
Below you find the current state of affairs the code is also available as part of the nicegui widgets project for which i am a comitter.
see dateparser.py
dateparser
"""
Created on 2023-12-03
@author: wf
"""
from dateutil import parser
import pytz
class DateParser:
"""A parser for converting date strings with timezone information into ISO 8601 format.
Attributes:
aliases (list): A list of tuples mapping timezone string aliases to their canonical form.
whois_timezone_info (dict): A dictionary mapping timezone abbreviations to their UTC offsets.
"""
def __init__(self):
# https://stackoverflow.com/a/54629675/1497139
self.aliases=[
("+0200 (MET DST)","+0200"),
(" METDST"," +0200"),
("(GMT)","+0000"),
("+0100 (Etc/GMT)","-0100"),
("Etc/GMT", "-0000"),
]
# Add generic aliases for a range of timezones
for hour in range(-12, 15): # Ranges from GMT-12 to GMT+14
sign = '+' if hour >= 0 else '-'
hour_abs = abs(hour)
# Example: ("(GMT+00:00)","+0000")
self.aliases.append((f"(GMT{sign}{hour_abs:02d}:00)", f"{sign}{hour_abs:02d}00"))
# Example: ("(GMT-1)","-0100"),
self.aliases.append((f"(GMT{sign}{hour})", f"{sign}0{hour_abs}00"))
# Handling Etc/GMT formats
# Example: ("Etc/GMT+1", "+0100")
gmt_sign = '' if hour <= 0 else '+'
self.aliases.append((f"Etc/GMT{gmt_sign}{hour}", f"{sign}{hour_abs:02d}00"))
self.timezone_hours = {
"AoE": {"offset": -12, "description": "Anywhere on Earth"},
"Y": {"offset": -12, "description": "Yankee Time Zone"},
"NUT": {"offset": -11, "description": "Niue Time"},
"SST": {"offset": -11, "description": "Samoa Standard Time"},
"X": {"offset": -11, "description": "X-ray Time Zone"},
"CKT": {"offset": -10, "description": "Cook Island Time"},
"HST": {"offset": -10, "description": "Hawaii Standard Time"},
"TAHT": {"offset": -10, "description": "Tahiti Time"},
"W": {"offset": -10, "description": "Whiskey Time Zone"},
"AKST": {"offset": -9, "description": "Alaska Standard Time"},
"GAMT": {"offset": -9, "description": "Gambier Time"},
"HDT": {"offset": -9, "description": "Hawaii-Aleutian Daylight Time"},
"V": {"offset": -9, "description": "Victor Time Zone"},
"AKDT": {"offset": -8, "description": "Alaska Daylight Time"},
"PST": {"offset": -8, "description": "Pacific Standard Time"},
"PT": {"offset": -8, "description": "Pacific Time"},
"U": {"offset": -8, "description": "Uniform Time Zone"},
"MST": {"offset": -7, "description": "Mountain Standard Time"},
"MT": {"offset": -7, "description": "Mountain Time"},
"PDT": {"offset": -7, "description": "Pacific Daylight Time"},
"T": {"offset": -7, "description": "Tango Time Zone"},
"CST": {"offset": -6, "description": "Central Standard Time"},
"CT": {"offset": -6, "description": "Central Time"},
"EAST": {"offset": -6, "description": "Easter Island Standard Time"},
"GALT": {"offset": -6, "description": "Galapagos Time"},
"MDT": {"offset": -6, "description": "Mountain Daylight Time"},
"S": {"offset": -6, "description": "Sierra Time Zone"},
"ACT": {"offset": -5, "description": "Acre Time"},
"CDT": {"offset": -5, "description": "Central Daylight Time"},
"CIST": {"offset": -5, "description": "Clipperton Island Standard Time"},
"COT": {"offset": -5, "description": "Colombia Time"},
"EASST": {"offset": -5, "description": "Easter Island Summer Time"},
"ECT": {"offset": -5, "description": "Ecuador Time"},
"EST": {"offset": -5, "description": "Eastern Standard Time"},
"ET": {"offset": -5, "description": "Eastern Time"},
"PET": {"offset": -5, "description": "Peru Time"},
"R": {"offset": -5, "description": "Romeo Time Zone"},
"AMT": {"offset": -4, "description": "Amazon Time"},
"AT": {"offset": -4, "description": "Atlantic Time"},
"BOT": {"offset": -4, "description": "Bolivia Time"},
"CIDST": {"offset": -4, "description": "Cambridge Bay Daylight Time"},
"CLT": {"offset": -4, "description": "Chile Standard Time"},
"EDT": {"offset": -4, "description": "Eastern Daylight Time"},
"FKT": {"offset": -4, "description": "Falkland Islands Time"},
"GYT": {"offset": -4, "description": "Guyana Time"},
"PYT": {"offset": -4, "description": "Paraguay Time"},
"Q": {"offset": -4, "description": "Quebec Time Zone"},
"VET": {"offset": -4, "description": "Venezuelan Standard Time"},
"AMST": {"offset": -3, "description": "Amazon Summer Time"},
"ART": {"offset": -3, "description": "Argentina Time"},
"BRT": {"offset": -3, "description": "Brasilia Time"},
"CLST": {"offset": -3, "description": "Chile Summer Time"},
"FKST": {"offset": -3, "description": "Falkland Islands Summer Time"},
"GFT": {"offset": -3, "description": "French Guiana Time"},
"P": {"offset": -3, "description": "Papa Time Zone"},
"PMST": {"offset": -3, "description": "Pierre & Miquelon Standard Time"},
"PYST": {"offset": -3, "description": "Paraguay Summer Time"},
"ROTT": {"offset": -3, "description": "Rothera Time"},
"SRT": {"offset": -3, "description": "Suriname Time"},
"UYT": {"offset": -3, "description": "Uruguay Time"},
"WARST": {"offset": -3, "description": "Western Argentina Summer Time"},
"WGT": {"offset": -3, "description": "West Greenland Time"},
"BRST": {"offset": -2, "description": "Brasilia Summer Time"},
"FNT": {"offset": -2, "description": "Fernando de Noronha Time"},
"O": {"offset": -2, "description": "Oscar Time Zone"},
"PMDT": {"offset": -2, "description": "Pierre & Miquelon Daylight Time"},
"UYST": {"offset": -2, "description": "Uruguay Summer Time"},
"WGST": {"offset": -2, "description": "West Greenland Summer Time"},
"AZOT": {"offset": -1, "description": "Azores Standard Time"},
"CVT": {"offset": -1, "description": "Cape Verde Time"},
"EGT": {"offset": -1, "description": "Eastern Greenland Time"},
"N": {"offset": -1, "description": "November Time Zone"},
"AZOST": {"offset": 0, "description": "Azores Summer Time"},
"EGST": {"offset": 0, "description": "Eastern Greenland Summer Time"},
"GMT": {"offset": 0, "description": "Greenwich Mean Time"},
"UT": {"offset": 0, "description": "Universal Time"},
"UTC": {"offset": 0, "description": "Coordinated Universal Time"},
"WET": {"offset": 0, "description": "Western European Time"},
"WT": {"offset": 0, "description": "Western Sahara Standard Time"},
"Z": {"offset": 0, "description": "Zulu Time Zone"},
"A": {"offset": 1, "description": "Alpha Time Zone"},
"CET": {"offset": 1, "description": "Central European Time"},
"MET": {"offset": 1, "description": "Middle European Time"},
"MEZ": {"offset": 1, "description": "Middle European Time"},
"WAT": {"offset": 1, "description": "West Africa Time"},
"WEST": {"offset": 1, "description": "Western European Summer Time"},
"B": {"offset": 2, "description": "Bravo Time Zone"},
"CAT": {"offset": 2, "description": "Central Africa Time"},
"CEDT": {"offset": 2, "description": "Central European Daylight Time"},
"CES": {"offset": 2, "description": "Central European Summer Time"},
"CEST": {"offset": 2, "description": "Central European Summer Time"},
"EET": {"offset": 2, "description": "Eastern European Time"},
"MES": {"offset": 2, "description": "Middle European Summer Time"},
"MEST": {"offset": 2, "description": "Middle European Summer Time"},
"MESZ": {"offset": 2, "description": "Middle European Summer Time"},
"MET DST": {"offset": 2, "description": "Middle European Time Daylight Saving Time"},
"SAST": {"offset": 2, "description": "South Africa Standard Time"},
"WAST": {"offset": 2, "description": "West Africa Summer Time"},
"NDT": {"offset": 2.5, "description": "Newfoundland Daylight Time"},
"AST": {"offset": 3, "description": "Arabia Standard Time"},
"C": {"offset": 3, "description": "Charlie Time Zone"},
"EAT": {"offset": 3, "description": "East Africa Time"},
"EEST": {"offset": 3, "description": "Eastern European Summer Time"},
"FET": {"offset": 3, "description": "Further-Eastern European Time"},
"IDT": {"offset": 3, "description": "Israel Daylight Time"},
"MSK": {"offset": 3, "description": "Moscow Time"},
"SYOT": {"offset": 3, "description": "Syowa Time"},
"TRT": {"offset": 3, "description": "Turkey Time"},
"IRST": {"offset": 3.5, "description": "Iran Standard Time"},
"NST": {"offset": 3.5, "description": "Newfoundland Standard Time"},
"ADT": {"offset": 4, "description": "Atlantic Daylight Time"},
"AZT": {"offset": 4, "description": "Azerbaijan Time"},
"D": {"offset": 4, "description": "Delta Time Zone"},
"GET": {"offset": 4, "description": "Georgia Standard Time"},
"GST": {"offset": 4, "description": "Gulf Standard Time"},
"KUYT": {"offset": 4, "description": "Kuybyshev Time"},
"MSD": {"offset": 4, "description": "Moscow Daylight Time"},
"MUT": {"offset": 4, "description": "Mauritius Time"},
"RET": {"offset": 4, "description": "Réunion Time"},
"SAMT": {"offset": 4, "description": "Samara Time"},
"SCT": {"offset": 4, "description": "Seychelles Time"},
"AFT": {"offset": 4.5, "description": "Afghanistan Time"},
"IRDT": {"offset": 4.5, "description": "Iran Daylight Time"},
"AQTT": {"offset": 5, "description": "Aqtobe Time"},
"AZST": {"offset": 5, "description": "Azerbaijan Summer Time"},
"E": {"offset": 5, "description": "Echo Time Zone"},
"MAWT": {"offset": 5, "description": "Mawson Station Time"},
"MVT": {"offset": 5, "description": "Maldives Time"},
"ORAT": {"offset": 5, "description": "Oral Time"},
"PKT": {"offset": 5, "description": "Pakistan Standard Time"},
"TFT": {"offset": 5, "description": "French Southern and Antarctic Time"},
"TJT": {"offset": 5, "description": "Tajikistan Time"},
"TMT": {"offset": 5, "description": "Turkmenistan Time"},
"UZT": {"offset": 5, "description": "Uzbekistan Time"},
"YEKT": {"offset": 5, "description": "Yekaterinburg Time"},
"IST": {"offset": 5.5, "description": "Indian Standard Time"},
"NPT": {"offset": 5.5, "description": "Nepal Time"},
"ALMT": {"offset": 6, "description": "Alma-Ata Time"},
"BST": {"offset": 6, "description": "Bangladesh Standard Time"},
"BTT": {"offset": 6, "description": "Bhutan Time"},
"F": {"offset": 6, "description": "Foxtrot Time Zone"},
"IOT": {"offset": 6, "description": "Indian Ocean Time"},
"KGT": {"offset": 6, "description": "Kyrgyzstan Time"},
"OMST": {"offset": 6, "description": "Omsk Time"},
"QYZT": {"offset": 6, "description": "Qyzylorda Time"},
"VOST": {"offset": 6, "description": "Vostok Station Time"},
"YEKST": {"offset": 6, "description": "Yekaterinburg Summer Time"},
"CCT": {"offset": 6.5, "description": "Cocos Islands Time"},
"MMT": {"offset": 6.5, "description": "Myanmar Time"},
"CXT": {"offset": 7, "description": "Christmas Island Time"},
"DAVT": {"offset": 7, "description": "Davis Time"},
"G": {"offset": 7, "description": "Golf Time Zone"},
"HOVT": {"offset": 7, "description": "Hovd Time"},
"ICT": {"offset": 7, "description": "Indochina Time"},
"KRAT": {"offset": 7, "description": "Krasnoyarsk Time"},
"NOVST": {"offset": 7, "description": "Novosibirsk Summer Time"},
"NOVT": {"offset": 7, "description": "Novosibirsk Time"},
"OMSST": {"offset": 7, "description": "Omsk Summer Time"},
"WIB": {"offset": 7, "description": "Western Indonesia Time"},
"AWST": {"offset": 8, "description": "Australian Western Standard Time"},
"BNT": {"offset": 8, "description": "Brunei Time"},
"CAST": {"offset": 8, "description": "Casey Time"},
"CHOT": {"offset": 8, "description": "Choibalsan Time"},
"H": {"offset": 8, "description": "Hotel Time Zone"},
"HKT": {"offset": 8, "description": "Hong Kong Time"},
"HOVST": {"offset": 8, "description": "Hovd Summer Time"},
"IRKT": {"offset": 8, "description": "Irkutsk Time"},
"KRAST": {"offset": 8, "description": "Krasnoyarsk Summer Time"},
"MYT": {"offset": 8, "description": "Malaysia Time"},
"PHT": {"offset": 8, "description": "Philippine Time"},
"SGT": {"offset": 8, "description": "Singapore Time"},
"ULAT": {"offset": 8, "description": "Ulaanbaatar Time"},
"WITA": {"offset": 8, "description": "Central Indonesia Time"},
"ACWST": {"offset": 8.75, "description": "Australian Central Western Standard Time"},
"AWDT": {"offset": 9, "description": "Australian Western Daylight Time"},
"CHOST": {"offset": 9, "description": "Choibalsan Summer Time"},
"I": {"offset": 9, "description": "India Time Zone"},
"IRKST": {"offset": 9, "description": "Irkutsk Summer Time"},
"JST": {"offset": 9, "description": "Japan Standard Time"},
"KST": {"offset": 9, "description": "Korea Standard Time"},
"PWT": {"offset": 9, "description": "Palau Time"},
"TLT": {"offset": 9, "description": "Timor Leste Time"},
"ULAST": {"offset": 9, "description": "Ulaanbaatar Summer Time"},
"WIT": {"offset": 9, "description": "Eastern Indonesia Time"},
"YAKT": {"offset": 9, "description": "Yakutsk Time"},
"ACST": {"offset": 9.5, "description": "Australian Central Standard Time"},
"MART": {"offset": 9.5, "description": "Marquesas Time"},
"AEST": {"offset": 10, "description": "Australian Eastern Standard Time"},
"AET": {"offset": 10, "description": "Australian Eastern Time"},
"CHUT": {"offset": 10, "description": "Chuuk Time"},
"ChST": {"offset": 10, "description": "Chamorro Standard Time"},
"DDUT": {"offset": 10, "description": "Dumont d'Urville Time"},
"K": {"offset": 10, "description": "Kilo Time Zone"},
"PGT": {"offset": 10, "description": "Papua New Guinea Time"},
"VLAT": {"offset": 10, "description": "Vladivostok Time"},
"YAKST": {"offset": 10, "description": "Yakutsk Summer Time"},
"YAPT": {"offset": 10, "description": "Yap Time"},
# Continuing from the previous part...
"ACDT": {"offset": 10.5, "description": "Australian Central Daylight Time"},
"LHST": {"offset": 10.5, "description": "Lord Howe Standard Time"},
"AEDT": {"offset": 11, "description": "Australian Eastern Daylight Time"},
"KOST": {"offset": 11, "description": "Kosrae Time"},
"L": {"offset": 11, "description": "Lima Time Zone"},
"LHDT": {"offset": 11, "description": "Lord Howe Daylight Time"},
"MAGT": {"offset": 11, "description": "Magadan Time"},
"NCT": {"offset": 11, "description": "New Caledonia Time"},
"NFT": {"offset": 11, "description": "Norfolk Time"},
"PONT": {"offset": 11, "description": "Pohnpei Time"},
"SAKT": {"offset": 11, "description": "Sakhalin Time"},
"SBT": {"offset": 11, "description": "Solomon Islands Time"},
"SRET": {"offset": 11, "description": "Srednekolymsk Time"},
"VLAST": {"offset": 11, "description": "Vladivostok Summer Time"},
"VUT": {"offset": 11, "description": "Vanuatu Time"},
"ANAST": {"offset": 12, "description": "Anadyr Summer Time"},
"ANAT": {"offset": 12, "description": "Anadyr Time"},
"FJT": {"offset": 12, "description": "Fiji Time"},
"GILT": {"offset": 12, "description": "Gilbert Island Time"},
"M": {"offset": 12, "description": "Mike Time Zone"},
"MAGST": {"offset": 12, "description": "Magadan Summer Time"},
"MHT": {"offset": 12, "description": "Marshall Islands Time"},
"NRT": {"offset": 12, "description": "Nauru Time"},
"NZST": {"offset": 12, "description": "New Zealand Standard Time"},
"PETST": {"offset": 12, "description": "Kamchatka Summer Time"},
"PETT": {"offset": 12, "description": "Kamchatka Time"},
"TVT": {"offset": 12, "description": "Tuvalu Time"},
"WAKT": {"offset": 12, "description": "Wake Island Time"},
"WFT": {"offset": 12, "description": "Wallis and Futuna Time"},
"CHAST": {"offset": 12.75, "description": "Chatham Standard Time"},
"FJST": {"offset": 13, "description": "Fiji Summer Time"},
"NZDT": {"offset": 13, "description": "New Zealand Daylight Time"},
"PHOT": {"offset": 13, "description": "Phoenix Island Time"},
"TKT": {"offset": 13, "description": "Tokelau Time"},
"TOT": {"offset": 13, "description": "Tonga Time"},
"CHADT": {"offset": 13.75, "description": "Chatham Daylight Time"},
"LINT": {"offset": 14, "description": "Line Islands Time"},
"TOST": {"offset": 14, "description": "Tonga Summer Time"},
"WST": {"offset": 14, "description": "West Samoa Time"}
}
# Convert timezone offsets from hours to seconds and create tzinfos dictionary
self.tzinfos = {}
for tz, info in self.timezone_hours.items():
offset_in_seconds = int(info["offset"] * 3600)
self.tzinfos[tz] = offset_in_seconds
def parse_date(self, date_str)->str:
"""
Parses a date string and converts it to ISO 8601 format.
Args:
date_str (str): The date string to be parsed.
Returns:
str: the ISO 8601 date string
"""
for alias, replacement in self.aliases:
date_str = date_str.replace(alias, replacement)
parsed_date = parser.parse(date_str,tzinfos=self.tzinfos)
parsed_date_z = parsed_date.astimezone(pytz.utc)
# Convert to ISO 8601 format
iso_date_str = parsed_date_z.isoformat()
iso_date_str_z= iso_date_str.replace("+00:00", "Z")
return iso_date_str_z
unit test
"""
Created on 2023-12-03
@author: wf
"""
from ngwidgets.basetest import Basetest
from ngwidgets.dateparser import DateParser
import json
class TestDateParser(Basetest):
"""
test date parser
"""
def test_aliases(self):
"""
test the aliases
"""
date_parser=DateParser()
debug=self.debug
if debug:
for org,repl in date_parser.aliases:
print(f"{org}->{repl}")
def test_dateparser(self):
"""
test the dateparser
"""
date_parser=DateParser()
test_cases = [
("Mon, 29 Mar 1999 16:12:30 -0330 (NST)","1999-03-29T12:42:30Z"),
("Wed, 17 May 2006 14:26:33 +0100 (Etc/GMT)","2006-05-17T15:26:33Z"),
("Fri May 1 11:50:05 2009 METDST","2009-05-01T09:50:05Z"),
("Wed, 25 Feb 2009 07:15:38 +0100 (GMT+01:00)","2009-02-25T06:15:38Z"),
("Fri, 21 Sep 2001 20:51:53 +0200 (MET DST)","2001-09-21T18:51:53Z"),
("Thu Jun 02 11:56:53 CDT 2011", "2011-06-02T16:56:53Z"), # Adjusted for UTC
("Wed, 16 Nov 2022 06:00:01 +0100", "2022-11-16T05:00:01Z"), # Adjusted for UTC
("Tue, 01 Jun 2004 11:09:50 +0200", "2004-06-01T09:09:50Z"), # Adjusted for UTC
# Add more test cases here
]
for date_input, expected_output in test_cases:
result = date_parser.parse_date(date_input)
self.assertEqual(result, expected_output, f"Failed for {date_input}")