Python时间戳的起点

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已于 2022-04-14 17:38:07 修改

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文章标签：时间数据类型 oracle datetime time 时间戳

于 2020-05-15 20:20:20 首次发布

本文链接：https://blog.youkuaiyun.com/Yellow_python/article/details/106125171

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系统时区为东八区
Python时间戳的起点为1970-01-01 08:00:00

代码验证

import datetime
print(datetime.datetime.fromtimestamp(0))

打印结果

1970-01-01 08:00:00

from time import strftime, localtime
print(strftime('%Y-%m-%d %H:%M:%S', localtime(0)))

打印结果

1970-01-01 08:00:00

时区

from datetime import datetime, timezone, timedelta

t = datetime(year=1970, month=1, day=1, hour=0, minute=0, second=0, microsecond=0,
             tzinfo=timezone(timedelta(hours=0)))
print(t)
print(t.timestamp())

t = datetime(year=1970, month=1, day=1, hour=8, minute=0, second=0, microsecond=0,
             tzinfo=timezone(timedelta(hours=8)))
print(t)
print(t.timestamp())

打印结果

1970-01-01 00:00:00+00:00
0.0
1970-01-01 08:00:00+08:00
0.0

相关应用

Python时间和毫秒互转

from datetime import datetime


def now() -> datetime:
    return datetime.now()


def str2datetime(s, fmt='%Y-%m-%d %H:%M:%S') -> datetime:
    return datetime.strptime(s, fmt)


def datetime2str(d, fmt='%Y-%m-%d %H:%M:%S') -> str:
    return d.strftime(fmt)


def datetime2second(d: datetime) -> float:
    return d.timestamp()


def datetime2millisecond(d: datetime) -> int:
    return int(d.timestamp() * 1000)


def second2datetime(f: float) -> datetime:
    return datetime.fromtimestamp(f)


def millisecond2datetime(ms: int) -> datetime:
    return second2datetime(ms / 1000)


t = datetime.now()
print(t)
sec = datetime2second(t)
print(sec)
t = second2datetime(sec)
print(t)

Oracle时间和毫秒互转

日期 -> 毫秒

SELECT
TO_NUMBER(
TO_DATE('2020-5-15 23:0:0','YYYY-MM-DD HH24:MI:SS')-TO_DATE('1970-01-01 8:0:0','YYYY-MM-DD HH24:MI:SS')
)*24*60*60*1000
FROM dual;

毫秒 -> 日期

SELECT
TO_CHAR(
1589554800000/(1000*60*60*24)+TO_DATE('1970-01-01 08:00:00','YYYY-MM-DD HH:MI:SS'),'YYYY-MM-DD HH24:MI:SS'
)FROM dual;