"Updated" date in UI different from modified_at from Python SDK

I'm trying to get the last time a file was modified. Checked the documentation and apparently what I need is to get the "modified_at" property.

The UI shows a completely different date:

Instead of getting Sep 25, I'm getting Sep 14 with the sdk.

This is the code I'm running:

from boxsdk import Client, OAuth2

auth = OAuth2(
    client_id='some_client_id',
    client_secret='some_client_secret',
    access_token='some_token',
)
client = Client(auth)

last_modified = client.file('some_id').get().modified_at

The content_modified_at property doesn't match either.

Am I missing something? Should I check another property?

Thanks!