Formula fields are fields whose value is calculated instead of being entered by the user. Using formula field, numbers, decimals and date manipulations can be done. The value of this field could be numeric or date depending on the output of the formula. In date manipulations, the result will be given in milliseconds, which you can format as per your need. We support +, - , * and / operators. Formula fields get recalculated automatically whenever the formula is changed. It also gets recalculated, when a field involved in the formula is changed.