Again not tested much

? DATETIME(YEAR(ltDt), MONTH(ltDt), DAY(ltDt), HOUR(ltDt), 0, 0) + ;
	CEILING((MINUTE(ltDT)*60 + SEC(ltDT))/(15*60)) * 15*60

>>Not tested

ltDt = DATETIME()
>>? DATETIME(YEAR(ltDt), MONTH(ltDt), DAY(ltDt), HOUR(ltDt), 0, 0) + ;
>>	IIF(MINUTE(ltDT)*60 + SEC(ltDT) >= 30*60, 1*60*60, 0)
>>

>>>
>>>How can I convert datetime() to the nearest hour?
>>>
> I also didn't specify the problem correctly. I always want to schedule for the future.
>
>I believe your code does what I want after I'd make minor adjustments.