A new H spec keyword, VALIDATE(*NODATETIME), is added for 6.1 and 7.1 through RPG compiler PTFs. The keyword indicates that date/time/timestamp validation will not necessarily be performed. A side-effect of this (and the reason for it) is that if validation is not required, there are some cases where d/t/z data can be treated as though it were alphanumeric data, making assignments and comparisons much faster. See this page in the RPG Cafe wiki for information about the keyword and the PTFs:
For the cases where the validation can be skipped, the performance differences can be quite spectacular. For a loop assigning one valid date to another 100 million times, 2 seconds vs 70 seconds. If the from-date is not valid, the non-validating program still takes 2 seconds because it just assigns the garbage. The validating program takes much much longer because it goes through exception handling for the errors. (I killed my program after a few minutes, but extrapolating from a run with fewer iterations suggests it would have taken over two hours.)
What makes this worth considering for most applications is that the incoming d/t/z data usually comes from database files. Database doesn't allow invalid d/t/z data, so input values are going to be valid, and even if the program calculates invalid values, they're not going to get stored in the file. Modules that handle wild d/t/z data, such as character dates entered by end-users, can leave off the keyword. Still, I wouldn't recommend using this keyword without a lot of analysis, both static analysis of the code to see where date/time/timestamp data is coming from, and of joblogs from test runs, looking for the RPG messages related to bad d/t/z data.