One thing I think that is fairly common is the desire to get the current datetime only up to a current precision, so you see a lot of things in, say, `dateutil` like this:

    dt = datetime.now().replace(hours=0, minutes=0, seconds=0, microseconds=0)

Or:

    dt = datetime.now().replace(microseconds=0)

I think it would make sense to add a `precision` keyword argument, similar to the `timespec` argument to isoformat (https://docs.python.org/3/library/datetime.html#datetime.datetime.isoformat), then you could just do:

dt = datetime.now(precision='day')

And get the current date as a datetime.