1. A method for customizing standard formula fields in a database system, the method comprising: receiving at least a portion of a formula for a standard database field of a standard database entity in a database system; storing a date range for maintaining at least the portion of the formula; calculating a value for the standard database field with at least the portion of the formula and information on one or more variables of the formula, wherein one or more database entities depend on the value for the standard database field; and storing the value for the standard database field.