The Problem
In this guide, we will explore exactly how to calculate days between dates in Excel. The tricky part is that "days between dates" can mean different things depending on what you are trying to measure.
Sometimes you want total calendar days. Other times you only want workdays. In some reports, you need a more human-friendly breakdown like years, months, and leftover days. If those are mixed up, the timeline can be misunderstood very quickly.
This challenge asks you to calculate all three views. You will find total days, working days, and a segmented date difference for each project, then complete a small summary section at the bottom.
How We Solve It
The first step is plain date subtraction for total days. After that, NETWORKDAYS handles working days, and DATEDIF breaks a date span into years, months, and days.
Putting those side by side is useful because each answer helps with a different kind of planning. Together they give a fuller view of how long each project runs.
Method 1: Date Subtraction
Method 1: Subtract one date from another to get total calendar days.
Excel stores dates as serial numbers, so subtracting one date from another returns the number of calendar days between them.
This is the simplest answer and a good starting point when weekends and holidays still count toward the timeline.
=C2-B2
Method 2: NETWORKDAYS for Workdays
Method 2: Count only working days by skipping weekends.
NETWORKDAYS is better when you want a planning-friendly number. It skips Saturdays and Sundays automatically, so the result is closer to the actual working time available.
That makes it useful for staffing, scheduling, and delivery estimates where weekends should not inflate the timeline.
=NETWORKDAYS(B2,C2)
Method 3: DATEDIF for Segments
Method 3: Break the difference into years, months, and remaining days.
DATEDIF is helpful when you want the result split into parts instead of one long number. In this challenge, it fills the Years, Months, and Days Left columns separately.
That is useful when the final audience is more comfortable reading a segmented duration than a raw day count.
Function Explanation
1. NETWORKDAYS
NETWORKDAYS returns the number of working days between two dates, excluding weekends. That makes it a better planning tool than simple subtraction when you want actual work time.
In this challenge, it helps show how a project timeline changes once non-working days are removed.
2. DATEDIF
DATEDIF returns the difference between two dates using a unit code like years, months, or days. It is useful when you want a more readable breakdown instead of a single total.
That is why it fits the last part of the challenge so well. Each unit answers a slightly different question about the same date span.
If you ever get an error here, check the date order first. The start date needs to come before the end date for the formulas in this challenge.
Calculate the timeline for each project in more than one way. Start with total calendar days, then count working days, and finally break the difference into years, months, and days. When the row formulas are finished, complete the summary so the worksheet also shows the total number of projects and the average total days.