CODEWITHSUNDEEP
pythonpandasdatetimetimestamp
debsim
debsim

Reputation: 666

Difference between pandas Timestamp and datetime

I was tinkering around with converting pandas.Timestamp to the built in python datetime. I tried the following:

pandas_time = pd.Timestamp(year=2020, day=4, month=2, hour=0, minute=0, second=1)
pandas_ts = pandas_time.timestamp()
datetime_time = datetime.datetime.fromtimestamp(pandas_ts)
datetime_ts = datetime_time.timestamp()

Looking at the variables gives this:

pandas_time:   2020-02-04 00:00:01
datetime_time: 2020-02-04 01:00:01
pandas_ts:   1580774401.0
datetime_ts: 1580774401.0

So they both have the same timestamp but the dates differ by one hour. When I tried it the other way around, I got this:

datetime_time = datetime.datetime(year=2020, day=4, month=2, hour=0, minute=0, second=1)
datetime_ts = datetime_time.timestamp()
pandas_time = pd.Timestamp(datetime_time)
pandas_ts = pandas_time.timestamp()

pandas_time:   2020-02-04 00:00:01
datetime_time: 2020-02-04 00:00:01
pandas_ts:   1580774401.0
datetime_ts: 1580770801.0

Now the dates are the same but the timestamps differ by 3600 (1 hour). I do know that I could use pandas to_pydatetime for conversion from pandas Timestamp to python datetime but I'm wondering why this difference occurs. Are their starting points defined differently? And if so, why?

Upvotes: 7

Views: 12187

Answers (1)

Epsi95
Epsi95

Reputation: 9047

If you look at the datetime documentation it is written for .fromtimestamp(timestamp)

classmethod date.fromtimestamp(timestamp) Return the local date corresponding to the POSIX timestamp, such as is returned by time.time().

So it returns local date. That's it. So you need to tell it to use utc explicitly whereas pandas uses utc by default.

pandas_time = pd.Timestamp(year=2020, month=2, day=4,  hour=0, minute=0, second=1)
pandas_ts = pandas_time.timestamp()
datetime_time = datetime.datetime.fromtimestamp(pandas_ts, tz=timezone.utc)
datetime_ts = datetime_time.timestamp()

Similarly for the second case

datetime_time = datetime.datetime(year=2020, day=4, month=2, hour=0, minute=0, second=1, tzinfo=timezone.utc)
datetime_ts = datetime_time.timestamp()
pandas_time = pd.Timestamp(datetime_time)
pandas_ts = pandas_time.timestamp()

From your question it seems you are living in a UTC+1 country :p

Upvotes: 8

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