Default timezone isn't utc?

[leafonsword]

From FAQ.
It also removes the notion of naive datetimes: each Pendulum instance is timezone-aware and by default in UTC for ease of use.
But from my test, seems dfault timezone is local machine's timezone, my machine's time zone is 'Asia/Shanghai'

>>> pendulum.now()                                                                                                                                               
<Pendulum [2018-01-05T15:51:55.975424+08:00]>       
                                                                                                             
>>> pendulum.now('Asia/Shanghai')                                                                                                                                
<Pendulum [2018-01-05T15:52:02.086741+08:00]>      
                                                                                                              
>>> pendulum.now().in_timezone('UTC')                                                                                                                            
<Pendulum [2018-01-05T07:52:27.614535+00:00]>                                                                                                                    
>>>                                                                                                                

So now() has same result like now('Asia/Shanghai'), not utc

[sethmlarson]

Can confirm in the code that Pendulum.now() uses datetime.datetime.now() not datetime.datetime.utcnow().

[pganssle]

@SethMichaelLarson I would certainly hope it doesn't use datetime.datetime.utcnow(). Even if you want a datetime in UTC you shouldn't use utcnow, you should use datetime.datetime.now(UTC) instead.

[sethmlarson]

Could you explain the difference between the two?
Pendulum uses datetime.datetime.utcnow().replace(tzinfo=UTC) for the UTC case.

[pganssle]

I will make a PR soon to remove the use of utcnow from Pendulum's internals, as it is pointless. You can see my comment here which explains why utcnow is a pointless aberration.

[sethmlarson]

Thanks for the clarification. I'd just say that a lot of us are here to learn and that programming with dates and times (even without timezones!) is really difficult, even for people who have a good control of the language.

[pganssle]

Looking at pendulum's interface more carefully, it seems like pendulum interprets naive datetimes as representing UTC, though Python assumes that they represent local time whenever a naive datetime is generated from some timezone-aware(ish) source, such as datetime.now, or when using datetime.astimezone. I think both choices are defensible, though the fact that they are different but intended to inter-operate probably causes some confusion.

@leafonsword I'm guessing that the reasons that pendulum.now() defaults to your local time are twofold:

1. pendulum is trying to be a more-or-less drop-in replacement for datetime, and datetime.now() (with no arguments) provides a naive datetime in local time.
2. pendulum.utcnow() can be used to get a datetime in UTC (and, unlike datetime.utcnow(), the datetime is not naive, assuaging my main problem with utcnow).

[leafonsword]

@pganssle Thx for your explaination~