Countdown & Calendar Calculators
Count days, weeks and months until any date. Track year progress, predict paydays, find quarter dates, explore moon phases, and count down to Christmas—all free and easy to use.
Choose a Calculator
Select a tool to show the inputs and results below.
Days Until Any Date
Find calendar days until or since any date.
Days Until Any Date
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Select a reference and target date. Dates are compared as local calendar dates; tomorrow is one calendar day away even if fewer than 24 hours remain.
Weeks Until Any Date
Count complete weeks, extra days, and decimal weeks.
Weeks Until Any Date
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Full weeks are the absolute calendar-day difference divided by 7, rounded down. The remaining days are shown separately.
Months Until Any Date
See completed calendar months and remaining days.
Months Until Any Date
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Completed calendar months are measured by advancing the earlier date, clamping days at each month end when required.
Days Left in the Year
Count the days remaining before December 31.
Days Left in the Year
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Counts days from a chosen date to December 31. Select Include date if you want the starting day counted too.
Weeks Left in the Year
Full weeks and remaining days before year-end.
Weeks Left in the Year
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Divides days remaining until December 31 by seven. It does not subtract ISO week numbers.
Months Left in the Year
Count later calendar months and days remaining.
Months Left in the Year
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Counts calendar months after the current month, and separately shows days remaining. This is not a fractional-month estimate.
Year Progress Calculator
See how much of the selected year has passed.
Year Progress Calculator
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Measures calendar days elapsed through the selected date, divided by 365 or 366 days in the year.
Paydays Calculator
Estimate upcoming weekly, biweekly, or monthly paydays.
Paydays Calculator
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Enter a known payday and schedule. Calculations do not shift dates around bank holidays or payroll policies.
Quarter Dates Calculator
Find fiscal quarter starts, ends and durations.
Quarter Dates Calculator
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Choose a fiscal year start month to generate four consecutive three-month quarters.
Moon Phases Calculator
Approximate lunar phase, illumination and lunar age.
Moon Phases Calculator
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Estimated phase from an average lunar period. Not a precise astronomical ephemeris or tide predictor.
Sleeps Until Christmas
Count the nights until Christmas morning.
Sleeps Until Christmas
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Each night from the chosen date through Christmas Eve is one sleep. Christmas Day itself has zero sleeps remaining.
Weekends Until Christmas
Count remaining Saturdays before Christmas.
Weekends Until Christmas
Accurate date calculations in your browser
Calculation results
CalculatedHow it works: Counts Saturdays strictly after the selected date and before Christmas Day. Each Saturday represents one upcoming weekend.
How to use the Countdown & Calendar tools
- Choose one of the twelve calculator tabs above.
- Enter the date, schedule, or year requested by your tool.
- Click Calculate → to get your result instantly.
- Use Copy Result to share the answer, or Try Example to learn the method.
Calendar days, weeks, and months are different
Calendar days are date-to-date differences. A complete week contains seven days, while calendar months have different lengths. We show these separately to make the result easier to interpret.
Countdowns and annual planning
Use the year-progress tools to track elapsed time, quarter dates for financial planning, and paydays for schedule estimates. Christmas sleep and weekend counters use a future December 25 date.
Moon phase calculation limits
The moon phase tool provides an approximate lunar age and illuminated fraction based on a mean synodic month, not exact astronomical phase times. Dates are interpreted using your selected calendar date.
Frequently asked questions
What is a calendar-day countdown?
It counts the difference between two calendar dates rather than the number of complete 24-hour periods. Tomorrow is one calendar day from today.
How are complete weeks calculated?
Divide the absolute day difference by seven and round down. The extra days are displayed separately.
How does the Months Until Calculator handle short months?
It advances complete calendar months from the earlier date, clamping a day such as the 31st to the last day of shorter months.
Does the Weeks Left in the Year tool use ISO week numbers?
No. It counts the days through December 31 and divides by seven, avoiding mistakes when an ISO year has 53 weeks.
Do payday dates automatically avoid public holidays?
No. Estimated schedules do not account for employer or bank policies, holidays, or delayed transfers.
Is the moon phase calculation astronomically exact?
No. It uses an average lunar cycle to provide an approximation. Astronomical phase times vary, so consult an ephemeris for precise events.
How are sleeps until Christmas counted?
One overnight counts as one sleep, so it is the calendar-day difference to December 25.
How are weekends until Christmas counted?
Each Saturday strictly after the reference day and before Christmas Day counts as one weekend. The current day and Christmas Day are excluded.
Can I use past dates?
Yes. General date countdown tools display absolute differences and tell you whether the target was earlier or later.
Does the calculator require signup or save dates?
No account is required and calculations run in your browser; this template does not send the input dates to a server.