20 calculator

Date & Time

Exact age in years, months, days, hours and minutes from birth date to any target date. Useful for legal documents,…

Days, weeks, months and years between two dates. Works in both directions.

Exact number of days between two dates — for projects, deadlines, holidays, contract terms. Handles leap years…

Converts date and time between any time zones. Essential for international meetings, remote teams and travel.

Local context: what changes in United States

Straight to the numbers — here is how Date & Time behaves under US rules, units and pricing conventions.

Money & format: Amounts are US dollars written as $1,234.56, with a period as the decimal mark. Sales tax is added at checkout, so advertised prices are pre-tax.
Tax structure: Federal income tax runs in brackets from 10% to 37%, on top of state income tax that ranges from 0% (TX, FL, WA) to over 13% (CA).
Payroll: FICA takes 7.65% from the employee (6.2% Social Security + 1.45% Medicare) and the employer matches it; Social Security stops at the annual wage base.
Units: Imperial by default: miles, pounds, °F, US gallons and feet/inches. A US gallon is 3.785 L, not the 4.546 L imperial gallon.
Power & standards: Households run on 120 V / 60 Hz with NEMA Type A/B plugs, and wiring sizes follow AWG under the NEC, not mm².

Example — Texas: A homeowner in Austin runs Date & Time with local rates, then checks the output against a contractor quote before signing.
Example — New York: A freelancer in NYC uses Date & Time to separate federal, state and city obligations before setting aside quarterly estimates.

Every figure above applies to United States specifically and is reviewed when the rules change.