I can see that it works but what is the meaning of the time int value.

Here is an example of why I say it is stored as a float.

with cte as (

select getdate() as date_format

, cast(getdate() as float) as date_as_float)

select date_format

, date_as_float

, floor(date_as_float) as date_int

, date_as_float - floor(date_as_float) as time_fraction

, floor((date_as_float - floor(date_as_float)) * 86400000) as time_in_ms

from cte;

If you take the time_in_ms and do the math you can get the hours, minutes, seconds and milliseconds (+/- a few ms).