Pandas strftime function prints unix epoch time in local TZ instead of UTC
I'm trying to convert a given date and time to unix epoch time using Pandas. This is normally a very straightforward thing to do, merely converting the string of date and time to a datetime object, and then printing the object as a unix epoch timestamp using strftime, for example:

`pd.to_datetime('2021-01-01 00:00:00').strftime('%s')`

Running the above example on a remote linux machine I have set up, whose system date is recorded in UTC, gets me the expected output of "1609459200" which is 2020-01-01 00:00:00 in unix epoch time. However, when pulling my code onto my Mac laptop and running locally has resulted in what was unexpected to me at first: that the above code prints off a unix epoch time 7 hours in advance, or a string reading "1609484400". 

Running the date command on my Mac OS terminal gives me the time in MST, which is where I live, instead of UTC like the remote linux machine I pulled my code from. MST is 7 hours behind UTC so I assume that Pandas is trying to account for the MST time recorded on my laptop and doing some kind of internal conversion. I figure that I need to specify that the time I'm inputing is UTC, so I tried that both with "utc=True" for `pd.to_datetime()` as well as "tz='UTC'" for `pd.Timestamp()`. No dice though, as I still get a return value of "1609484400". 

Output when running with pd.to_datetime():
> dt = pd.to_datetime('2021-01-01 00:00:00', utc=True)
> dt
> ->Timestamp('2021-01-01 00:00:00+0000', tz='UTC')
> 
> dt.strftime('%Y-%m-%d %H:%M:%S')
> -> '2021-01-01 00:00:00'  # Converting back to the original format gives me the original string
> 
> dt.strftime('%B %d, %Y, %r')
> -> 'January 01, 2021, 12:00:00 AM'  # Expected output
> 
> dt.strftime('%s')
> -> '1609484400'  # This is '2021-01-01 07:00:00+00:00' in unix epoch time (7 hours ahead)
> 
> dt.tz_convert('MST').strftime('%s')
> -> '1609484400'  # Converting the timezone to MST before strftime strangely produces the same result

The exact same outputs occurred using `pd.Timestamp()` with the timezone set to either UTC or MST. Again, the expected output for `dt.strfime('%s')` should be "1609484400" in UTC, and I'm confused why I can't produce this value on my local machine. I know I could try to futz around with my Mac's system date, or hardcode a solution into my script by subtracting 7 hours from the dt object, but I don't want to change my Mac's system date, nor do I want to hardcode a solution into the script residing on my local machine. Am I doing something wrong or fundamentally misunderstanding something here, or is this a bug for the epoch time printoff for strftime? 

I am using:
Pandas version 1.2.0
Mac OS version 10.13.6

Thanks in advance for your help!


