Calculating Date Differences, Working Days, and Durations

Date arithmetic is notoriously tricky due to varying month lengths (28 to 31 days), leap years, and weekend/business day calculations.

Perform accurate date math with our free Date Calculator.

Common Date Calculation Scenarios

1. Elapsed Time Between Two Dates: Exact breakdown in years, months, weeks, days, hours, and minutes.
2. Adding/Subtracting Offsets: Determining a future due date (e.g. Start Date + 45 business days).
3. Workday / Business Day Calculation: Excluding Saturdays, Sundays, and public holidays from project sprint timelines.

// JavaScript UTC date difference in days
function getDayDifference(dateA, dateB) {
  const MS_PER_DAY = 1000 * 60 * 60 * 24;
  const utcA = Date.UTC(dateA.getFullYear(), dateA.getMonth(), dateA.getDate());
  const utcB = Date.UTC(dateB.getFullYear(), dateB.getMonth(), dateB.getDate());
  return Math.floor((utcB - utcA) / MS_PER_DAY);
}

Calculate project deadlines and time differences accurately with the Date Calculator.