date column + WITH FILL timestamp return meaningless dates. #30421
Description
Describe the unexpected behaviour
If you will try to use date column with WITH FILL based on DateTime values ClickHouse will silently overflow values.
Which can be unexpected if you use toStartOfInterval functions with MONTH / WEEK / DAY / HOUR precision, because some of them returns Date and some of them return DateTime.
How to reproduce
ClickHouse 21.11
SELECT today() AS a
ORDER BY a ASC WITH FILL FROM now() - toIntervalMonth(1) TO now() + toIntervalDay(1) STEP 82600
┌──────────a─┐
│ 2021-10-20 │
└────────────┘
┌──────────a─┐
│ 2105-12-14 │
│ 1973-03-29 │
│ 2019-12-17 │
│ 2066-09-05 │
│ 2113-05-26 │
│ 1980-09-08 │
│ 2027-05-29 │
│ 2074-02-15 │
│ 2120-11-05 │
│ 1988-02-19 │
│ 2034-11-08 │
│ 2081-07-28 │
│ 2128-04-17 │
│ 1995-08-01 │
│ 2042-04-20 │
│ 2089-01-07 │
│ 2135-09-28 │
│ 2003-01-11 │
│ 2049-09-30 │
│ 2096-06-19 │
│ 2143-03-10 │
│ 2010-06-23 │
│ 2057-03-12 │
│ 2103-12-01 │
│ 1971-03-16 │
│ 2017-12-03 │
│ 2064-08-22 │
│ 2111-05-13 │
│ 1978-08-26 │
│ 2025-05-15 │
│ 2072-02-02 │
│ 2118-10-23 │
│ 1986-02-05 │
└────────────┘
34 rows in set. Elapsed: 0.013 sec.
SELECT today() AS a
ORDER BY a ASC WITH FILL FROM now() - toIntervalSecond(1) TO now() + toIntervalSecond(1) STEP 1
┌──────────a─┐
│ 2021-10-20 │
└────────────┘
┌──────────a─┐
│ 2025-07-01 │
│ 2025-07-02 │
└────────────┘
Expected behavior
Disallow mixing Date/DateTime datatypes here or correctly convert them.