First thing: What the heck is that do i= loop in there for? Your shown code would loop over the exact same values however many times the value of &Ct may be. One almost might guess that once upon a time this iterated over the values of one of the arrays testing each value but this code doesn't. You aren't referencing either of the arrays using i as an index.   Hint: If an array of numeric values returns missing, as in max(of hra_ (*)) = . the min will ALWAYS be missing as the only way the Max and Min functions return missing is when all values are missing. So the bit of and min(of hra_(*)) = . is not needed and adds additional () that aren't actually needed after removing the min. Alternate code could also be to test if all values are missing. nmiss(of hra_(*)) = dim(hra_a) The bit of max(of hra_ (*)) = min(of hra_ (*)) Could be replaced with Range( of hra_(*))=0 Range is largest non-missing minus smallest non-missing. So when the max and min are the same the range is 0.   Note: You may also need to consider Leap years some where if that is why you are hard coding 365. ... View more

See this: proc format; invalue ustz "AST" = 14400 /* ATLANTIC STANDARD TIME UTC - 4 */ "EST" = 18000 /* EASTERN STANDARD TIME UTC - 5 */ "EDT" = 14400 /* EASTERN DAYLIGHT TIME UTC - 4 */ "CST" = 21600 /* CENTRAL STANDARD TIME UTC - 6 */ "CDT" = 18000 /* CENTRAL DAYLIGHT TIME UTC - 5 */ "MST" = 25200 /* MOUNTAIN STANDARD TIME UTC - 7 */ "MDT" = 21600 /* MOUNTAIN DAYLIGHT TIME UTC - 6 */ "PST" = 28800 /* PACIFIC STANDARD TIME UTC - 8 */ "PDT" = 25200 /* PACIFIC DAYLIGHT TIME UTC - 7 */ "AKST" = 32400 /* ALASKA TIME UTC - 9 */ "AKDT" = 28800 /* ALASKA DAYLIGHT TIME UTC - 8 */ "HST" = 36000 /* HAWAII STANDARD TIME UTC - 10 */ "HAST" = 36000 /* HAWAII-ALEUTIAN STANDARD TIME UTC - 10 */ "HADT" = 32400 /* HAWAII-ALEUTIAN DAYLIGHT TIME UTC - 9 */ "SST" = 39600 /* SAMOA STANDARD TIME UTC - 11 */ "SDT" = 36000 /* SAMOA DAYLIGHT TIME UTC - 10 */ "CHST" = -36000 /* CHAMORRO STANDARD TIME UTC +10 */ other = 0 ; data want; infile datalines; input dttime e8601dt16. zone :$4.; format dttime e8601dt19.; dttime = dttime + input(zone,ustz.); drop zone; datalines; 2020-07-14 11:00 EDT ; The result will be the datetime in UTC. ... View more