I would like too schedule a job to execute once every tree months (and also once every year). E.g January 1'th, April 1'th, Juli 1'th and October 1'th. Is it possible to do this in 24x7?

Sure, it is possible. Create a job of script type that will run on FIRST DAY OF EVERY MONTH. I the job script write something like the following

Dim MonthNumber, number
DateTimePart "@T"mm/dd/yyyy"", "mm", MonthNumber
ChooseCase MonthNumber, END
Case 1, 4, 7, 10

Dim process, number

Run "[put your program name here]", "", process
END:

The same you can do for programs that should run once a year, just specify an appropriate CASE statement.

: I would like too schedule a job to execute once every tree months (and also
: once every year). E.g January 1'th, April 1'th, Juli 1'th and October
: 1'th. Is it possible to do this in 24x7?