将本地 unix 时间转换为 UTC unix 时间的问题

Question

我正在尝试将我本地系统上的 unix 时间转换为 unix 格式的 UTC 时间，但在转换之后，最终时间将减少 +1 小时。

为此，我编写了以下代码。

from dateutil import tz 
import time
from time 
import mktime

now_time = time.time()
print('current local unix time', now_time)
print(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(now_time)))

to_zone = tz.tzutc()
from_zone = tz.tzlocal()    

t = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(now_time))
utc = datetime.strptime(str(t), '%Y-%m-%d %H:%M:%S')
utc = utc.replace(tzinfo=from_zone)

central = utc.astimezone(to_zone)
print('Converted to UTC ',central)

unix_secs = mktime(central.timetuple())

print('Central unix time ',unix_secs)
print('central unix time to dattime ', time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(unix_secs)))

输出结果如下

current local unix time 1563985835.3707478
2019-07-24 12:30:35
Converted to UTC  2019-07-24 16:30:35+00:00
Central unix time  1564003835.0
central unix time to dattime  2019-07-24 17:30:35

有人可以告诉我我做错了什么吗？我该如何解决这个问题？

Answer 1

我猜你在使用 time.strftime 和之后 datetime.strptime 或使用 mktime 将时间戳转换为 datetime 实例时错误地使用 TZ 信息转换日期时间。

无论如何，有更简单的方法来实现你想要的：

from datetime import datetime, timezone

# Get current timestamp

now_timestamp = time.time()
>> 1563987839.054703

# Get datetime of that timestamp but already in UTC.
# This preserves TZ information and allows 
# to correctly do transition to the timestamp again.

utc_time = datetime.utcfromtimestamp(now_timestamp)
>> datetime.datetime(2019, 7, 24, 17, 3, 59, 54703)

# Convert UTC datetime back to timestamp

utc_timestamp = utc_time.timestamp()
>> 1563977039.054703

# Verify that this timestamp is indeed UTC
# I am in UTC+3 timezone now

datetime.now()
>> datetime.datetime(2019, 7, 24, 20, 4, 10, 500229)

datetime.fromtimestamp(utc_timestamp)
>> datetime.datetime(2019, 7, 24, 17, 3, 59, 54703)

Answer 2

Unix 时间戳始终采用 UTC。

是"the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, UTC"。

换句话说，就是时长。在何处进行此计算一点也不重要。减法在宇宙中无处不在。持续时间与时区完全无关。

参考 - https://en.wikipedia.org/wiki/Unix_time

将本地 unix 时间转换为 UTC unix 时间的问题

Problem in converting local unix time to UTC unix time

python

time

datetime

unix-timestamp