Python 如何比较不同时区的时间

在本文中，我们将展示如何使用以下方法比较不同时区的时间。

将给定时区与本地时区进行比较
比较两个时区的当前日期时间
比较具有不同时区的两个时间

方法1：将给定时区与本地时区进行比较

步骤

以下是执行所需任务的算法/步骤：

使用import关键字，导入datetime，pytz模块。
使用pytz模块的timezone()函数（获取特定位置的时区）获取”CET”（本地时区）的时区，并将其存储在一个变量中。
使用timezone()函数获取UTC时区，并将其存储在另一个变量中。
使用datetime的astimezone()函数（astimezone()函数用于在DateTime模块中修改DateTime类的对象）通过将本地时区作为参数传递给它来将上述时间转换为另一个时区。
打印本地和UTC时区的值。
使用if条件语句比较本地时区的值是否等于UTC时区，并根据结果进行打印。

以下程序在比较本地时区和给定时区后返回用户消息：

示例

# importing datetime, pytz modules
from datetime import datetime
import pytz
# Getting the local timezone
localTimeZone = pytz.timezone('CET')
# Getting the UTC timeZone
utcTimeZone = datetime.now(pytz.utc)
# format string
format = '%Y:%m:%d %H:%M:%S %Z %z'
# Convert the time to the local timezone
local = utcTimeZone.astimezone(localTimeZone)
# Getting formatted time using strftime() function
print("Formatted DateTime in Local Timezone : ",local.strftime(format))
print("Formatted DateTime in UTC Timezone : ",utcTimeZone.strftime(format))
difference = int(local.strftime('%z'))
difference2 = int(utcTimeZone.strftime('%z'))
# Comparing Time Zones
if (difference > difference2):
   print('UTC TimeZone is behind the Local Timezone by',local.strftime('%z'),'Hours')
if(difference < difference2):
   print('UTC TimeZone is ahead of the Local TimeZone by',utcTimeZone.strftime('%z'),'Hours')

输出

Formatted DateTime in Local Timezone :  2022:09:14 12:05:05 CEST +0200
Formatted DateTime in UTC Timezone :  2022:09:14 10:05:05 UTC +0000
UTC TimeZone is behind the Local Timezone by +0200 Hours

方法2：比较两个时区的当前日期时间

时区可能会让事情变得更加复杂，但幸运的是，我们可以使用相同的逻辑进行比较。唯一的区别是，我们正在使用带有有关所在时区的附加信息的已知日期。

步骤

以下是执行所需任务的算法/步骤：

使用import关键字导入datetime（Python有一个名为datetime的模块用于处理日期和时间），以及pytz模块（使我们的原始日期变得可知）。
使用pytz模块的timezone()函数（获取特定位置的时区）获取“America/New_York”的时区。
使用pytz模块的timezone()函数（获取特定位置的时区）获取“Europe/London”的时区。
使用datetime.now()函数获取当前日期时间。
使用localize()函数将上述时区转换为本地化函数。

localize() function
When creating datetime-aware objects with an initial fixed datetime value, the correct function to use is localise(). The original datetime value will be retained in the resulting datetime aware object.

现在两个时间在同一个时区
根据要求使用条件语句比较时区

示例

# importing datetime, pytz modules
from datetime import datetime
import pytz
# Getting the time in America/New_York timezone
timezone_newyork= pytz.timezone('America/New_York')
# Getting the time in Europe/London timezone
timezone_london = pytz.timezone("Europe/London")
# current datetime
inputDatetime = datetime.now()
# Localize the given date, according to the timezone objects
# Here this step converts the given two timezones to local time zones using localize() function
datewith_tz_newyork = timezone_newyork.localize(inputDatetime)
datewith_tz_london = timezone_london.localize(inputDatetime)
# These are now, effectively no longer the same *date* after being localized
print("The date and time with timezone newyork:", datewith_tz_newyork)
print("The date and time with timezone london:", datewith_tz_london)
difference = int(datewith_tz_newyork.strftime('%z'))
difference2 = int(datewith_tz_london.strftime('%z'))
# checking whether the date with different timezones are equal or NOT after they are in the same timezone
if(datewith_tz_newyork > datewith_tz_london):
 print('Current Time in Newyork time is older than London by',(difference2- difference)/100,'hours')
else:
 print('Current Time in London time is older than Newyork by',(difference- difference2)/100,'hours')

输出

The date and time with timezone newyork: 2022-09-14 10:13:27.727111-04:00
The date and time with timezone london: 2022-09-14 10:13:27.727111+01:00
Current Time in Newyork time is older than London by 5.0 hours

方法3：比较不同时区的两个时间

这与前面的方法类似，只是我们提供了两个时区的DateTime。

示例

from datetime import datetime
import pytz
# Getting the time in America/New_York timezone
timezone_newyork= pytz.timezone('America/New_York')
# Getting the time in Europe/London timezone
timezone_london = pytz.timezone("Europe/London")
# input the date time of the newyork in the format Year, Month, Day, Hour, Minute, Second
newyorkDateTime = datetime(2013, 3, 15, 20, 5, 10)
#input date time of the london
londonDateTime = datetime(2013, 3, 15, 20, 5, 10)
# Localize the given date, according to the timezone objects
datewith_tz_newyork = timezone_newyork.localize(newyorkDateTime)
datewith_tz_london = timezone_london.localize(londonDateTime)
# These are now, effectively no longer the same *date* after being localized
print("The date and time with timezone newyork:", datewith_tz_newyork)
print("The date and time with timezone london:", datewith_tz_london)
difference = int(datewith_tz_newyork.strftime('%z'))
difference2 = int(datewith_tz_london.strftime('%z'))
# comparingthe date with different timezonesafter they are in the same timezone
if(difference > difference2):
   print('Given Two Times of two different Time Zones are equal',(difference-difference2)/100,'hours')
else:
   print('Given Two Times of two different Time Zones are not equal by',(difference2-difference)/100,'hours')

输出

The date and time with timezone newyork: 2013-03-15 20:05:10-04:00
The date and time with timezone london: 2013-03-15 20:05:10+00:00
Given Two Times of two different Time Zones are not equal by 4.0 hours