The end of Daylight Saving Time (DST) also varies by country and region, but it is usually set by government authorities to occur on a specific date and time each year. In most countries that observe DST, the end date falls on a weekend to minimize disruption to business and daily life.
In the United States, DST typically ends on the first Sunday in November at 2:00 am local time. At that time, clocks are moved back by one hour, so 2:00 am becomes 1:00 am. This change results in one hour more of daylight in the morning, but one hour less of daylight in the evening.
It's important to note that not all countries observe DST, and even those that do may have different start and end dates. For example, in the European Union, the end of DST is usually on the last Sunday in October, but some countries may have different rules.
In Python, you can use the pytz library to convert between local time and UTC time, taking into account DST rules for the specified time zone. Here's an example of using pytz to calculate the end time of DST for the US Eastern time zone in 2023:
import datetimeimport pytz# create a datetime object for the start of 2023dt = datetime.datetime(2023, 1, 1, 0, 0, 0)# create a timezone object for the US Eastern time zonetz = pytz.timezone('US/Eastern')# get the localized time for the end of DST in 2023dst_end = tz.localize(dt.replace(month=11, day=1, hour=2), is_dst=None)# get the UTC time for the end of DSTdst_end_utc = dst_end.astimezone(pytz.utc)print(dst_end)# output: 2023-11-05 02:00:00-04:00print(dst_end_utc)# output: 2023-11-05 06:00:00+00:00 |
In this example, we create a datetime object for the start of 2023 and a timezone object for the US Eastern time zone. We then use the localize() method to attach the time zone information to the datetime object and set the is_dst parameter to None to indicate that we don't know whether DST is in effect at that time. We replace the month and day to calculate the end of DST in the US Eastern time zone in 2023, and then use the astimezone() method to convert the local time to UTC time, taking into account the DST rules for the specified time zone.