Is >= x is used to specify a range of values greater than or equal to the value x. x can be of any type: Number, Currency, Date, Time, DateTime, and String.
Examples
Is >= 250
The range of all numbers greater than or equal to 250.
Is >= CDate (2000, 3, 17)
The range of dates from March 17, 2000 onwards including March 17, 2000.