Methodology & Calculation Standards

Calendar-based tools use JavaScript Date objects normalized to UTC for day-level calculations. Exact age and date-difference modes respect real month lengths and leap years rather than treating every month as thirty days. Estimation calculators identify their simplified models and should not be treated as clinical, legal, financial or official determinations. Boundary testing should include leap days, month ends, reversed ranges, birthday boundaries and values near user-entered thresholds. Static calculator forms execute in the browser; production analytics or hosting technologies should be described separately in the privacy policy.

Calendar-based tools use JavaScript Date objects normalized to UTC for day-level calculations. Exact age and date-difference modes respect real month lengths and leap years rather than treating every month as thirty days. Estimation calculators identify their simplified models and should not be treated as clinical, legal, financial or official determinations. Boundary testing should include leap days, month ends, reversed ranges, birthday boundaries and values near user-entered thresholds. Static calculator forms execute in the browser; production analytics or hosting technologies should be described separately in the privacy policy.

Calendar-based tools use JavaScript Date objects normalized to UTC for day-level calculations. Exact age and date-difference modes respect real month lengths and leap years rather than treating every month as thirty days. Estimation calculators identify their simplified models and should not be treated as clinical, legal, financial or official determinations. Boundary testing should include leap days, month ends, reversed ranges, birthday boundaries and values near user-entered thresholds. Static calculator forms execute in the browser; production analytics or hosting technologies should be described separately in the privacy policy.

Calendar-based tools use JavaScript Date objects normalized to UTC for day-level calculations. Exact age and date-difference modes respect real month lengths and leap years rather than treating every month as thirty days. Estimation calculators identify their simplified models and should not be treated as clinical, legal, financial or official determinations. Boundary testing should include leap days, month ends, reversed ranges, birthday boundaries and values near user-entered thresholds. Static calculator forms execute in the browser; production analytics or hosting technologies should be described separately in the privacy policy.