Welcome back to our Global Excel Solutions series! As part of our Week 10: Dates, Times, & Financials journey, we are diving into Post 1: Essential Date and Time Formulas Every Professional Should Know.
Working with dates in Excel can be incredibly frustrating if you don't know the right functions—especially when subtracting two dates returns a weird 1900s serial number instead of the actual days between them.
Here is the exact formula cheat sheet to automate your timelines and deadlines:
Always Show Today's Date:
=TODAY() (Updates automatically every time you open the workbook)
Calculate Business Days Between Two Dates:
=NETWORKDAYS(Start_Date, End_Date) (Automatically excludes weekends)
Find the Last Day of a Month:
=EOMONTH(Start_Date, Months_to_add) (Perfect for calculating invoice due dates)
Full breakdown + step-by-step video guide below:
Why Date Formulas Matter
Dates in Excel are actually stored as serial numbers behind the scenes. That means you can add and subtract them like regular numbers. But doing it manually doesn't account for weekends, leap years, or different month lengths. Excel's built-in time formulas handle all that complex calendar math for you in the background.
Step-by-Step Implementation
Dynamic Dashboards with TODAY: Click a cell and type =TODAY(). Use this in your dashboard headers or summary cards so your reports always show the current date without you ever having to manually type it.
Project Timelines with NETWORKDAYS: Got a start date in A2 and an end date in B2? Type =NETWORKDAYS(A2, B2) to see exactly how many working days your team has to complete the project, ignoring Saturdays and Sundays.
Invoice Deadlines with EOMONTH: If an invoice is issued in cell A2 and is due at the end of the following month, use =EOMONTH(A2, 1). Excel will automatically calculate the exact last day of next month.
Top Use Cases for Date Formulas
Project Management: Map out strict business-day delivery schedules without manually counting weeks on a calendar.
Accounts Receivable: Automatically flag overdue invoices by using conditional formatting to highlight rows where the due date is less than =TODAY().
HR Tracking: Calculate exact employee tenure or days accrued for PTO using dynamic date differences.
Pro Tip: Always make sure the cells containing your formulas are formatted correctly! If you type a date formula and get a random number like 45800, your formula worked perfectly—Excel just needs you to go to the Home tab and change the cell format from "General" to "Short Date".
