Convert Python time to Matlab datum

How do I convert Python timestamp to a Matlab datenum? I am sure this is a common issue, but I could not find a Matlab function to do this easily.

Answer 1

[Dave B]

Python has several ways it represents time. A common one is so called unix timestamps, which are the number of seconds since 1970:

secssince1970 = 1634287957.292;
datetime(1970,1,1) + seconds(secssince1970)

ans = datetime
   15-Oct-2021 08:52:37

[Dave B]

@Mark Davidson - if this answer is not working for you, can you send us an example timestamp? As @Steven Lord described, you should use datetime not datenum. If you really have to use a datenum (e.g. for some legacy code) just call datenum on the datetime value:

ts_unix = 1634287957.292;
dt_matlab = datetime(1970,1,1) + seconds(ts_unix)

dt_matlab = datetime
   15-Oct-2021 08:52:37

dn_matlab = datenum(dt_matlab)

dn_matlab = 7.3844e+05

[Mark Davidson]

The timestamp I have is:

1546300800 which in Python returns...

01/01/2019, 00:00:00

[Dave B]

So I think the datetime(1970,1,1) + seconds(unitxtime) approach gives the answer you're looking for:

a=datetime(1970,1,1) + seconds(1546300800)

a = datetime
   01-Jan-2019

% note you can format datetimes however you like:
a.Format = 'MM/dd/uuuu, HH:mm:ss'

a = datetime
   01/01/2019, 00:00:00

[Mark Davidson]

Here is the Python code if that's at all helpful?

from datetime import datetime

timestamp = 1546300800

date_time = datetime.fromtimestamp(timestamp)

d = date_time.strftime("%m/%d/%Y, %H:%M:%S")

print("Output 1:", d)

Output 1: 01/01/2019, 00:00:00

[Dave B]

I think I'm still confused about what's missing:

timestamp = 1546300800;
date_time = datetime(1970,1,1) + seconds(timestamp);
date_time.Format = 'MM/dd/uuuu, HH:mm:ss';
fprintf("Output 1: %s\n", date_time)	

Output 1: 01/01/2019, 00:00:00

[Mark Davidson]

Perfect! Thank you.

[Mark Davidson]

This might be a useful Matlab fuction...

function [dnum,date_time]=python2matlabTime(timestamp)

date_time = datetime(1970,1,1) + seconds(timestamp);

dnum=datenum(date_time);

return

Answer 2

[Steven Lord]

Don't convert to a datenum. Depending on how the Python timestamp represents the date and time, I suspect some of the values for the ConvertFrom parameter in the datetime function will be of use, something like:

x = 20211015;
dt = datetime(x, 'ConvertFrom', 'yyyymmdd')

dt = datetime
   15-Oct-2021

[Mark Davidson]

The time-stamp is in a number format a bit like the matlab datenumber but not the same. I think that it is the same as the unix timestamp, but I'm not sure.