We have a wide selection of date-time calculators. Since periods affect so many aspects of our lives, date and time math are tasks we perform daily, if not hourly. Our tools make it easy to set calendar events and reminders, calculate the time between events or other dates of interest, add or remove days or minutes from a specified timestamp, and much more. Our date and time calculators can help estimate the amount of hours worked, create weekly time cards, and much more.