Subtracting negative timedelta around DST not same as adding the positive

[tomage]

Hey! As I've been digging deeper into the Pendulum library, I've discovered one interesting edge-case: Namely that for specific times, subtracting a negative timedelta is not the same as adding the positive one.

Thus, my_dt - my_negative_timedelta is not equal to my_dt + (-my_negative_timedelta).

As before, I took the liberty of throwing together what seemed a sensible patch: #419.

Here's also a pyfiddle, to see this in action: https://pyfiddle.io/fiddle/6a20e200-bb3a-4af9-b336-a216f868487d/.

Thanks!

[teresatruex]

I am seeing the same issue! Is this a bug? Please let us know!

[shuyang-truex]

I'm experiencing the same issue, my code snippet below:

import pendulum
from pendulum import datetime
from datetime import timedelta

la_tz = pendulum.timezone('America/Los_Angeles')

d = datetime(2019, 11, 4, hour=0, tzinfo=la_tz)

and console output:

>>> d - timedelta(hours=24)
<Pendulum [2019-11-03T00:00:00-07:00]>
>>> d + timedelta(hours=-24)
<Pendulum [2019-11-03T01:00:00-07:00]>

Hope we can get some attention from the maintainers on this issue.

[tomage]

Fixed with #419 (comment)!