Calculating Key Dates From September to May

The school year runs roughly from September to May with summer break in between. Knowing how to calculate key dates in this September to May period is useful for students, teachers, parents and anyone planning events tied to the academic calendar.

In this article, we’ll look at how to find the number of days between two dates, add or subtract days, weeks months and years, calculate based on weekdays, and define holiday settings.

We’ll also overview some background on calendars and holidays to provide context for date calculations. Let’s get started!

Counting Days, Weeks, Months and Years Between Dates

A handy tool for finding the time span between two dates is a date calculator.

Simply enter a start and end date and the calculator will find the number of years, months, weeks and days in between. Results take into account leap years and other calendar quirks.

Some key options include:

• Including or excluding the end date.

• Defining holidays to exclude from counts.

• Limiting counts to business days only.

Knowing the number of days from September to May helps with planning out lesson schedules, assignment due dates and tests.

Adding or Subtracting Time Periods from Dates

Date calculators can also add or subtract specified time periods from a start date.

You can enter a date then add or subtract any number of:

• Years
• Months
• Weeks
• Days

This allows you to quickly find new dates in the future or past. For the school calendar, you could add 180 days to find the end of the typical school year. Or subtract 3 months to find the start of summer vacation.

Results adjust for different month lengths and leap years based on the calendar.

Calculating Based on Weekdays Only

When scheduling events, you often want to exclude weekend days.

Date calculators let you specify “business days only” which skips Saturdays and Sundays in counts. You can also choose to exclude defined holidays too.

This gives weekday-only time spans, useful for planning a multi-day conference or calculating working weeks between September and May.

Defining Holiday Settings

Date calculators allow you to customize exactly which holiday dates are excluded from counts:

• Option to not count any holidays.

• Default major US federal holidays.

• Add custom holiday dates.

Defining holidays like Thanksgiving, Winter Break and Spring Break improves calculations for academic schedules.

You can also view federal holidays for current and future years as a reference.

Understanding Calendar Systems

To fully utilize date calculations, it helps to understand some calendar basics:

• The Gregorian calendar is the standard calendar system used today.

• Years have 365 days, with a leap day added to February 29 in leap years.

• Months have set lengths, with 28/29 days in February.

• The calendar aligns with the solar cycle by adding leap days.

• Replacing the earlier Julian calendar in 1582 corrected drift.

Major Holidays Overview

Some key points about holidays:

• Holidays commemorate events or honor significant people/groups.

• Holiday dates can be fixed (like New Year’s Day) or float based on day of week.

• Countries observe national, cultural and religious holidays.

• Government holidays close non-essential offices and schools.

• Individual companies decide which holidays to observe.

• Holiday pay may apply for working federal holidays.

• Custom holidays can be added to date calculations.

Putting It All Together

• Find exact days between start and end dates.

• Add or subtract time periods from a fixed start date.

• Limit calculations to weekdays only.

• Define major holidays like Thanksgiving to exclude.

• Reference federal holiday dates for the current school year.

• Understand calendar features like leap years.

• Allow for floating dates like Spring Break.

Accurately calculating dates for the school year helps teachers, students, parents and administrators plan schedules, activities, assignments and events. With the powerful options available in date calculators, you can customize date math to suit any need.

So next time you’re planning for the academic year, turn to handy date calculators to save time and effort. Knowing exactly how many days there are from September to May has never been easier!