How To Calculate Difference Between Two Dates In Excel 2013

Calculate the difference between two dates in days, months, or years with Excel 2013 formulas

Calculating the difference between two dates is one of the most common tasks in Excel 2013, whether you’re tracking project timelines, calculating employee tenure, or analyzing financial periods. This comprehensive guide will walk you through all the methods available in Excel 2013 to calculate date differences accurately.

Basic Date Difference

The simplest way to find the difference between two dates is to subtract them directly. Excel stores dates as sequential numbers, so this calculation gives you the number of days between dates.

Formula: =End_Date - Start_Date

DATEDIF Function

The DATEDIF function is specifically designed for date calculations and offers more flexibility than simple subtraction. It can return differences in days, months, or years.

Syntax: =DATEDIF(start_date, end_date, unit)

YEARFRAC Function

For precise fractional year calculations (useful in financial contexts), YEARFRAC provides accurate results based on different day count conventions.

Syntax: =YEARFRAC(start_date, end_date, [basis])

Method 1: Simple Date Subtraction

The most straightforward method to calculate the difference between two dates in Excel 2013 is to simply subtract one date from another. This works because Excel stores dates as sequential serial numbers starting from January 1, 1900 (date 1).

Steps to Use Simple Subtraction:

1. Enter your start date in cell A1 (e.g., 1/15/2013)
2. Enter your end date in cell B1 (e.g., 5/20/2014)
3. In cell C1, enter the formula: =B1-A1
4. Press Enter to see the result in days

By default, Excel will display the result as a date serial number. To format it as days:

1. Right-click on the result cell
2. Select “Format Cells”
3. Choose “Number” with 0 decimal places

Limitations:

• Only returns days (not months or years)
• Doesn’t account for different month lengths
• Basic formatting required for readable output

Method 2: Using the DATEDIF Function

The DATEDIF function is Excel’s built-in function specifically designed for date calculations. Despite being a “hidden” function (it doesn’t appear in the function library), it’s fully supported in Excel 2013 and provides more flexibility than simple subtraction.

DATEDIF Syntax:

=DATEDIF(start_date, end_date, unit)

Where unit can be:

• "D" – Complete days between dates
• "M" – Complete months between dates
• "Y" – Complete years between dates
• "YM" – Months remaining after complete years
• "MD" – Days remaining after complete months
• "YD" – Days remaining after complete years

Practical Examples:

Scenario	Formula	Result	Explanation
Total days between dates	=DATEDIF(A1,B1,"D")	490	Days between 1/15/2013 and 5/20/2014
Complete months between dates	=DATEDIF(A1,B1,"M")	16	Full months between the dates
Complete years between dates	=DATEDIF(A1,B1,"Y")	1	Full years between the dates
Years and months format	=DATEDIF(A1,B1,"Y") & " years, " & DATEDIF(A1,B1,"YM") & " months"	“1 years, 4 months”	Combined years and months

Important Notes About DATEDIF:

• Always put the earlier date first in the function
• If the end date is earlier than the start date, you’ll get a #NUM! error
• The function rounds down to complete units (e.g., 1 year and 11 months would return 1 year)
• For more precise calculations, you may need to combine multiple DATEDIF functions

Method 3: Using YEARFRAC for Fractional Years

The YEARFRAC function calculates the fraction of the year represented by the number of whole days between two dates. This is particularly useful in financial calculations where you need precise year fractions.

YEARFRAC Syntax:

=YEARFRAC(start_date, end_date, [basis])

The optional basis argument specifies the day count basis to use:

• 0 or omitted – US (NASD) 30/360
• 1 – Actual/actual
• 2 – Actual/360
• 3 – Actual/365
• 4 – European 30/360

Practical Applications:

1. Financial Calculations: Accurate interest calculations over partial years
2. Project Management: Precise allocation of resources over time periods
3. Data Analysis: Normalizing time periods for comparison

Basis	Description	Example (1/15/2013 to 5/20/2014)	Result
0 (US 30/360)	Assumes 30 days per month, 360 days per year	=YEARFRAC(A1,B1,0)	1.3611
1 (Actual/actual)	Uses actual days and actual year length	=YEARFRAC(A1,B1,1)	1.3425
2 (Actual/360)	Uses actual days but 360-day year	=YEARFRAC(A1,B1,2)	1.3611
3 (Actual/365)	Uses actual days but 365-day year	=YEARFRAC(A1,B1,3)	1.3425
4 (European 30/360)	Similar to US 30/360 but with different end-of-month rules	=YEARFRAC(A1,B1,4)	1.3611

Method 4: Combining Functions for Complete Results

For the most comprehensive date difference calculations, you’ll often need to combine multiple functions to get years, months, and days separately.

Complete Date Difference Formula:

To get a result like “X years, Y months, Z days”, use this combined formula:

=DATEDIF(A1,B1,"Y") & " years, " & DATEDIF(A1,B1,"YM") & " months, " & DATEDIF(A1,B1,"MD") & " days"

Alternative Approach with Separate Cells:

1. Years: =DATEDIF(A1,B1,"Y")
2. Months: =DATEDIF(A1,B1,"YM")
3. Days: =DATEDIF(A1,B1,"MD")
4. Combined result: =C1 & " years, " & D1 & " months, " & E1 & " days"

Handling Edge Cases:

• Negative Results: Use =ABS(DATEDIF(...)) to always get positive numbers
• Blank Cells: Wrap in IF statements: =IF(OR(A1="",B1=""),"",DATEDIF(A1,B1,"D"))
• Date Validation: Use ISNUMBER to check for valid dates

Common Errors and Solutions

Error	Cause	Solution
#NUM!	End date is earlier than start date	Swap the dates or use ABS function
#VALUE!	One or both cells contain non-date values	Ensure both cells contain valid dates or use date functions to create proper dates
######	Column isn’t wide enough to display the result	Widen the column or adjust the number format
Incorrect month calculation	DATEDIF counts complete months only	Use additional calculations for partial months or consider using EDATE function

Advanced Techniques

Calculating Weekdays Between Dates

To count only weekdays (excluding weekends) between two dates:

=NETWORKDAYS(start_date, end_date)

For custom weekend parameters or to exclude holidays:

=NETWORKDAYS(A1,B1,holidays_range)

Calculating Age from Birth Date

To calculate someone’s age based on birth date:

=DATEDIF(birth_date,TODAY(),"Y")

For more precise age including months:

=DATEDIF(birth_date,TODAY(),"Y") & " years, " & DATEDIF(birth_date,TODAY(),"YM") & " months"

Working with Times as Well as Dates

When your dates include time components, you can:

• Subtract to get exact decimal days: =B1-A1
• Format as [h]:mm to see hours and minutes
• Use =HOUR(B1-A1) to extract just the hours

Best Practices for Date Calculations in Excel 2013

1. Always use proper date formats: Ensure your dates are recognized as dates by Excel (right-aligned in cells by default)
2. Use date functions for creation: =DATE(year,month,day) instead of typing dates directly
3. Document your formulas: Add comments to explain complex date calculations
4. Validate inputs: Use data validation to ensure only dates can be entered
5. Consider time zones: If working with international dates, account for time zone differences
6. Test edge cases: Always test with dates that span month-end, year-end, and leap years
7. Use helper columns: For complex calculations, break them into steps in separate columns

Real-World Applications

Project Management

• Tracking project durations
• Calculating time between milestones
• Resource allocation based on time periods

Human Resources

• Calculating employee tenure
• Tracking time between reviews
• Vacation accrual calculations

Finance

• Interest calculations over periods
• Amortization schedules
• Investment holding periods

Manufacturing

• Production cycle times
• Equipment maintenance schedules
• Warranty period tracking

Excel 2013 vs. Newer Versions

Feature	Excel 2013	Excel 2016+
DATEDIF function	Available (hidden)	Available (hidden)
New date functions	Not available	DAYS, DAYS360, etc.
Dynamic arrays	Not available	Available (spill ranges)
Date formatting options	Basic	Enhanced
Power Query integration	Limited	Full integration

Learning Resources

For more advanced Excel date calculations, consider these authoritative resources:

• Microsoft Official DATEDIF Documentation
• Harvard University Excel Resources
• IRS Publication 5093 (Date Calculations for Tax Purposes)

Frequently Asked Questions

Why does Excel show ###### instead of my date difference?

This typically means the column isn’t wide enough to display the result. Either widen the column or change the number format to a more compact display (like General format for days).

How do I calculate the difference in hours between two dates?

Multiply the day difference by 24: =(B1-A1)*24. Format the result cell as Number with 2 decimal places.

Can I calculate business days excluding holidays?

Yes, use the NETWORKDAYS function with a range containing your holiday dates: =NETWORKDAYS(A1,B1,holidays_range).

Why does DATEDIF sometimes give unexpected month results?

DATEDIF counts complete months only. For example, between Jan 31 and Mar 1, it counts as 1 month because Feb 31 doesn’t exist. For more precise month calculations, you might need additional formulas.

How do I handle dates before 1900 in Excel 2013?

Excel 2013 doesn’t natively support dates before 1900. You would need to store these as text and convert them using custom functions or VBA macros for calculations.

Can I calculate the difference between times without dates?

Yes, use the same subtraction method but with time values only. Format the result cell as [h]:mm:ss to properly display time differences over 24 hours.

Conclusion

Mastering date calculations in Excel 2013 opens up powerful possibilities for data analysis, project management, and financial modeling. While Excel 2013 may not have all the modern date functions found in newer versions, the combination of simple subtraction, DATEDIF, and YEARFRAC provides robust tools for nearly any date calculation scenario.

Remember these key points:

• Simple subtraction gives you days between dates
• DATEDIF offers flexible year/month/day calculations
• YEARFRAC provides precise fractional year calculations
• Combining functions gives you complete control over date difference formatting
• Always validate your inputs and test edge cases

As you become more comfortable with these techniques, you’ll find increasingly creative ways to apply date calculations to solve real-world problems in your spreadsheets.