Date Calculator: Find Duration & Add/Subtract Dates

Calculate the duration (years, months, days) between two dates, or find a new date by adding or subtracting time. Accurate, accessible, and mobile-friendly.

Full original guide (expanded)

Audit: Complete

Formula (LaTeX) + variables + units

This section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)

\[= (selector) => document.querySelectorAll(selector); const elements = { form: $('#calculator-form'), tabs:\]

= (selector) => document.querySelectorAll(selector); const elements = { form: $('#calculator-form'), tabs:

Formula (extracted text)

$TotalDays = \lfloor \frac{Timestamp_{End} - Timestamp_{Start}}{1000 \times 60 \times 60 \times 24} \rfloor$

Variables and units

No variables provided in audit spec.

Sources (authoritative):

Home — calcdomain.com · Accessed 2026-01-19
https://calcdomain.com/
Everyday Life — calcdomain.com · Accessed 2026-01-19
https://calcdomain.com/lifestyle-everyday
Time and Date — calcdomain.com · Accessed 2026-01-19
https://calcdomain.com/subcategories/time-date
Age Calculator — calcdomain.com · Accessed 2026-01-19
https://calcdomain.com/age-calculator
Time Duration Calculator — calcdomain.com · Accessed 2026-01-19
https://calcdomain.com/time-duration-calculator

Changelog

Version: 0.1.0-draft
Last code update: 2026-01-19

0.1.0-draft · 2026-01-19

Initial audit spec draft generated from HTML extraction (review required).
Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
Confirm sources are authoritative and relevant to the calculator methodology.

Verified by Ugo Candido on 2026-01-19
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Formulas

(Formulas preserved from original page content, if present.)

Version 0.1.0-draft

Citations

Add authoritative sources relevant to this calculator (standards bodies, manuals, official docs).

Changelog

0.1.0-draft — 2026-01-19: Initial draft (review required).