Function: DAYS()

📘 Definition:

The DAYS() function calculates the number of days between two dates.
It helps in finding the duration or gap between a start date and an end date — for example, the number of days between two billing dates, project timelines, or student admissions.

🧩 Syntax: DAYS(end_date, start_date)


• end_date → The ending date of the period

• start_date → The starting date of the period

🧠 Example (Indian Perspective):

This shows how many days are between important Indian timeline examples (like quarterly accounting periods or national events).

🪜 Step-by-Step Explanation:

1. Suppose A2 = 01-Apr-2024, B2 = 30-Jun-2024

2. Formula → =DAYS(B2, A2)

3. Excel calculates the difference:
   30-Jun-2024 – 01-Apr-2024 = 90 days

4. Output → 90

If the start date is after the end date, Excel returns a negative number.

💡 Tip:

If your dates are stored as text, convert them using DATEVALUE() before using DAYS():

🎯 Why It’s Useful:

• To calculate durations between admission, due, or expiry dates.

• For project management or student EMI period tracking.

• To find how long someone has worked or studied.

🧑‍💻 Project Task 1: Student Admission to Course Completion Duration

👉 Tasks:

1. Use =DAYS(C2, B2) to calculate Course Duration (Days).

2. Format the result as a number.

3. Identify which student had the longest course duration.

🧑‍💻 Project Task 2: Payment Due Days Calculation

👉 Tasks:

1. Calculate the number of days between Invoice Date and Payment Received Date using DAYS().

2. Highlight all records where payment was made after 10 days using Conditional Formatting.