The Complete Guide to Timezone Conversion for Developers
Master timezone conversion as a developer. Learn how UTC offsets, IANA timezones, DST, and ISO 8601 work, and avoid common pitfalls.
Jun 17, 2026
Calculate exact difference between two dates in all time units with business days option.
A date difference calculator computes the exact duration between two dates. It calculates the precise difference in years, months, days, hours, minutes, and seconds.
This tool features:
The difference is calculated by subtracting the start date from the end date. The calculator accounts for leap years and varying month lengths to give the most accurate result.
Business days are weekdays (Monday through Friday), excluding weekends (Saturday and Sunday). When enabled, the calculator counts only these days in the date range.
Yes. The calculator automatically detects which date is earlier and calculates accordingly. You can enter dates in any order.
Yes. All processing happens entirely in your browser. No data is sent to any server.
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