Filtering by TimestampField in Postgres
Solved. [Docs](http://docs.peewee-orm.com/en/latest/peewee/api.html?highlight=trunc#Database.truncate_date).
```
today_events = events.select().where(fn.date_trunc('day', fed_events.created_at) == datetime.date.today())
```
Hello!

I'm trying to filter queryset I got from remote Postgres DB by TimestampField, and can't find out the timestamp format to cast.
I tried:
`today_events = events.select().where(fed_events.created_at > '2017-08-25 00:00:00')`
`today_events = events.filter(fed_events.created_at > '2017-08-25 00:00:00')`
`today_events = events.filter(fed_events.created_at > 1503604800.0)`
Also tried datetimes.

I get errors like "You may need to cast the value explicitly".
Do I miss something?

Best Regards,
Alexey