Cast from pl.Date to pl.Datetime silently returns incorrect value when new dtype cannot hold value

[mcrumiller]

Checks

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of Polars.

Reproducible example

When attempting to cast pl.Date to pl.Datetime("ns"), the date changes, when perhaps we should raise instead:

from datetime import date
import polars as pl

# lower date limit for nanosecond
pl.Series([date(1677, 9, 22)]).cast(pl.Datetime("ns")) # 1677-09-22 00:00:00
pl.Series([date(1677, 9, 21)]).cast(pl.Datetime("ns")) # 2262-04-11 23:34:33.709551616

# upper date limit for nanosecond
pl.Series([date(2262, 4, 11)]).cast(pl.Datetime("ns"))  # 2262-04-11 00:00:00
pl.Series([date(2262, 4, 12)]).cast(pl.Datetime("ns"))  # 1677-09-21 00:25:26.290448384

Installed versions

main

[mcrumiller]

@MarcoGorelli

[MarcoGorelli]

thanks for the ping