21.2:

```
milovidov-desktop :) SELECT CAST(1111111111.222 AS DateTime64(3))

SELECT cast(1111111111.222, 'DateTime64(3)')

Query id: d10c8623-5c74-4a38-b535-a99f6af4d28d

┌─cast(1111111111.222, 'DateTime64(3)')─┐
│               2005-03-18 04:58:31.222 │
└───────────────────────────────────────┘
```

master:

```
milovidov-desktop :) SELECT CAST(1111111111.222 AS DateTime64(3))

SELECT cast(1111111111.222, 'DateTime64(3)')

Query id: cb4af967-a4ae-4df5-89ba-234d68675f93

┌─cast(1111111111.222, 'DateTime64(3)')─┐
│               2005-03-18 04:58:31.000 │
└───────────────────────────────────────┘
```
if (from_is_unsigned == to_is_unsigned)
                return {true, true, true};
            if (!to_is_unsigned)
                return {true, true, true};
            
            if (left_in_first_half == right_in_first_half)
                return {true};
            return {};
        }
        
        if (size_of_from > size_of_to)
        {
            
            if (left.isNull() || right.isNull())
                return {};
            
            if (divideByRangeOfType(left.get<UInt64>()) != divideByRangeOfType(right.get<UInt64>()))
                return {};
            if (to_is_unsigned)
                return {true};
            else
                
                return {(T(left.get<UInt64>()) >= 0) == (T(right.get<UInt64>()) >= 0)};
        }
        __builtin_unreachable();
    }
};
struct ToDateMonotonicity
{
    static bool has() { return true; }