DatePart function in ANSI SQL

Hi folks,

How can I re-write the following code in ANSI SQL code:

select cast(datepart(month, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar) + '/' +
cast(datepart(day, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar) + '/'+ cast(datepart(year, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar), event_instance_id, max(time_stamp)
from usmuser.usm_sli_event_data
where event_instance_id=10019
group by cast(datepart(month, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar) + '/' +
cast(datepart(day, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar) + '/'+
cast(datepart(year, dateadd(second, time_stamp, '1/1/1970 00:00:00')) as varchar),
event_instance_id
order by event_instance_id

Thanks for your help!
-Parulcould you please explain why?

also, for those of us not patient enough to unravel the intricacies of this delectable code fragment, would you kindly please explain what it's doing|||The code should be portable so it can used be used on other databases as well, not just SQL Server.
Basically, the time_stamp field has number of seconds since 1/1/1970 and the datepart function is calculating the month, day, and year. The goal is to get the last time_stamp per event_instance_id per day.|||unfortunately, your quest will be unsatisfied

date functions are among the more un-robust of the ANSI SQL capabilities

there is practically no hope that you will get exactly the same code to run "on other databases as well, not just SQL Server"

even if we did manage to figure out a way to do what you're doing with ANSI SQL functions (and good luck to you, as i'm going to pass), it probably wouldn't run on SQL Server to start with|||This is what data abstraction layers are for...|||Thanks r937!