calculating time cards

Use this calculator to add or subtract two or more time values in the form of an expression. best credit cards travel points An acceptable input has d, h, m, and s following each value, where d means days, h means hours, m means minutes, and s means seconds The only acceptable operators are + and - "1d 2h 3m 4s + 4h 5s - 2030s" is an example of a valid expression