How do I create a datetime in Python from milliseconds?

How do I create a datetime in Python from milliseconds? I can create a similar Date object in Java by java.util.Date(milliseconds).

Allocates a Date object and initializes it to represent the specified number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT.

5 Answers

Just convert it to timestamp

datetime.datetime.fromtimestamp(ms/1000.0) 

What about this? I presume it can be counted on to handle dates before 1970 and after 2038.

target_datetime_ms = 200000 # or whatever base_datetime = datetime.datetime(1970, 1, 1) delta = datetime.timedelta(0, 0, 0, target_datetime_ms) target_datetime = base_datetime + delta 

as mentioned in the Python standard lib:

fromtimestamp() may raise ValueError, if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions. It’s common for this to be restricted to years in 1970 through 2038.

Very obviously, this can be done in one line:

target_dt = datetime(1970, 1, 1) + timedelta(milliseconds=target_dt_ms) 

Converting millis to datetime (UTC):

import datetime time_in_millis = 1596542285000 dt = datetime.datetime.fromtimestamp(time_in_millis / 1000.0, tz=datetime.timezone.utc) 

Converting datetime to string following the RFC3339 standard (used by Open API specification):

from rfc3339 import rfc3339 converted_to_str = rfc3339(dt, utc=True, use_system_timezone=False) # 2020-08-04T11:58:05Z 

Bit heavy because of using pandas but works:

import pandas as pd pd.to_datetime(msec_from_java, unit='ms').to_pydatetime() 

import pandas as pd Date_Time = pd.to_datetime(df.NameOfColumn, unit='ms')