All Date & Time Calculators
8 free date and time tools — live holiday countdowns, date calculators, and business day counters. Everything runs in your browser.
When to use a date calculator
Date math is easy to get wrong when weekends, deadlines, holidays, and time zones are involved. These calculators are meant for everyday planning: counting days until an event, checking how much time is left before a deadline, or finding the number of business days between two dates. Use them when a calendar count matters more than a rough mental estimate.
Countdowns vs. date math
Countdown pages answer a live question, such as how long until Christmas or New Year. Calculator pages answer a planning question, such as adding days to a start date or counting business days. If you are planning work, travel, school, or paperwork, start with the calculator group. If you only need a live timer, use the countdown group.
Holiday Countdowns
Date Calculators
Days Between Two Dates Calculator
Calculate the exact number of days between any two dates. Includes weeks, months...
Business Days Calculator
Calculate the number of business days (weekdays) between two dates. Excludes wee...
Date Add/Subtract Calculator
Add or subtract days, weeks, or months from any date. Free online date calculato...
How Many Days Old Am I?
Find out exactly how many days old you are. Enter your birthday and see your age...
How these date tools handle accuracy
These tools use your browser to calculate dates instantly. For deadline-sensitive work, always confirm the final date against the rules of the organization involved, because courts, schools, employers, airlines, and government offices may define weekends, holidays, and cut-off times differently. The calculators are best used as a fast planning aid, then checked against the official policy when the date has legal, financial, or travel consequences.