Date and time formula learning path

Excel Date Functions Guide

Work with dates, deadlines, business days, months, and age calculations using Excel date and time functions.

Date formulas that solve real work

  • Use TODAY and NOW for dynamic dates that update automatically.
  • Use EDATE and EOMONTH for month-based deadlines, renewals, and reporting periods.
  • Use WORKDAY and NETWORKDAYS when weekends and holidays should be excluded.

Avoid date errors

  • Make sure Excel recognizes dates as serial date values, not plain text.
  • Use DATE to build reliable dates from year, month, and day values.
  • Check regional date formats when importing data from another country.

Practical date and time workflow

  • Confirm dates are serial numbers (format as General briefly) before DATEDIF or comparisons.
  • Store holidays on a dedicated range for NETWORKDAYS instead of hard-coding each holiday in formulas.
  • Use EDATE and EOMONTH for billing cycles — document whether due dates land on business days.
  • Separate date entered from date calculated to simplify audit trails on contracts and SLAs.

Recommended next steps

  • TODAY and NOW for dynamic headers; EDATE and EOMONTH for billing cycles and month-end reporting.
  • DATEDIF or simple subtraction for tenure, age, and SLA day counts — confirm calendar vs business days.
  • NETWORKDAYS when weekends and holidays must be excluded from elapsed-time KPIs.
  • Watch for dates stored as text — they break DATEDIF and most comparison formulas until converted.

Date formulas used in operations

  • Contract end: =EDATE(StartDate,TermMonths) with EOMONTH when terms align to month-end.
  • Age in years: =DATEDIF(BirthDate,TODAY(),"Y") — verify BirthDate is a real date serial.
  • SLA breach flag: =IF(NETWORKDAYS(OpenDate,ClosedDate)>TargetDays,"Breached","OK").
  • Rolling window start: =TODAY()-30 for dashboards filtered to last thirty calendar days.

People also ask

  • Why does DATEDIF return #NUM!? Start date after end date, or text dates not recognized by Excel.
  • TODAY vs NOW? TODAY is date-only; NOW includes time — pick based on whether time-of-day matters.
  • WORKDAY vs NETWORKDAYS? WORKDAY adds N business days to a start; NETWORKDAYS counts business days between two dates.

Deep-dive function map for Excel Date Functions Guide

  • TODAY (/functions/today/): Returns the current date. Updates automatically when the worksheet recalculates. Example: =TODAY().
  • NOW (/functions/now/): Returns the current date and time. Example: =NOW().
  • DATE (/functions/date/): Creates a date from year, month, and day components. Example: =DATE(2026, 1, 21).
  • EDATE (/functions/edate/): Returns a date that is a specified number of months before or after a given date. Example: =EDATE(TODAY(), 3).
  • EOMONTH (/functions/eomonth/): Returns the last day of the month, a specified number of months before or after a date. Example: =EOMONTH(TODAY(), 0).
  • WORKDAY (/functions/workday/): Returns a date that is a specified number of working days before or after a start date. Example: =WORKDAY("1/1/2024", 10).
  • NETWORKDAYS (/functions/networkdays/): Returns the number of whole working days between two dates, excluding weekends and holidays. Example: =NETWORKDAYS("1/1/2024", "1/31/2024").
  • DATEDIF (/functions/datedif/): Calculates the number of days, months, or years between two dates. Example: =DATEDIF(A1, B1, "Y").

Two-week study plan

  • Week 1 — Read each related function page and copy one example per function into a practice Table.
  • Week 2 — Apply this guide to a real export from your job; document fixes in a changelog tab.
  • Explore categories: Date & Time.
  • Run the fix-excel-formula-errors checklist when any formula shows #N/A, #VALUE!, #REF!, or #SPILL!.
  • Compare similar functions (VLOOKUP vs XLOOKUP, SUMIF vs SUMIFS) before standardizing team templates.
  • Export a PDF snapshot of your completed practice workbook for future reference and onboarding.

Error and troubleshooting cross-links

  • Fix #VALUE! (/errors/value-error/) — step-by-step causes and solutions in the error directory.
  • Fix #NUM! (/errors/num/) — step-by-step causes and solutions in the error directory.