>I have been using a substring of the SYS(2015) variable to generate these names and today, for the first time in two years, the substring is starting with numbers. Didn't occur to me to check the leading character when I wrote the code. I have changed the function that generates these temp file names to always start them with a character. Thanks, Sergey.

Hi Margaret,

In short, the value returned by the SYS(2015)function is based on the system clock and includes date (as # of days from some point in time) in the first 3 characters after "_". Yesterday that value was '0ZZ' and today it's '100'. For more details see Convert SYS(2015) value back File #9704.