DateWise

A date and age calculator — exact age, date differences, business days, and calendar-aware date math, all on-device.

Calendar arithmetic is not subtraction. Months vary between 28 and 31 days, so "two months and three days" depends on which two months, and any calculation that divides elapsed days by an average month length drifts by a day or two in ways that look arbitrary.

Business-day counting adds a second layer, since it depends on which days count as weekend and which holidays apply — both vary by country, and some regions observe a Friday-Saturday weekend. Any tool has to pick a convention and be explicit about it, because a contract deadline computed under the wrong one is wrong by days.