Business days between dates
Calculate business days between two dates.
Countdown to a date
Count the days remaining or elapsed from a target date.
Date in X days
Add or subtract days from a date.
Day of the week
Find the weekday for any date.
Day of year
Find the rank of a date within the year.
Days between dates
Simply calculate the number of days between two dates.
Exact age
Calculate an exact age in years, months and days.
ISO weeks in a year
List all ISO weeks in a year.
Leap years
Check a year or list leap years within an interval.
Monthly calendar
Display and print a clear monthly calendar.
Months between dates
Calculate the number of months between two dates.
Printable year calendar
Prepare a printable calendar over several months.
Quarters between dates
Calculate the number of quarters between two dates.
Week number
Find the ISO week number for a date.
Weeks between dates
Calculate the number of weeks between two dates.
About these tools
AppErgo’s date tools cover common calendar needs: finding the weekday, identifying a week number, counting down to a deadline, adding or subtracting days, or checking the rank of a date within the year. Several tools are designed to provide a clear result immediately, without manual calculation.
The category also includes planning-oriented tools, such as the monthly calendar, the printable year calendar, and the ISO week list for a year. They help prepare useful references for personal organization, administrative tasks, project tracking, or schedule planning.