Dates & Times: TODAY, DATEDIF, EOMONTH¶

Because dates are serial numbers (Chapter 2), Excel can do real date arithmetic — ages, durations, deadlines.

A project timeline with dates and durations

Today & Now¶

excel

2 lines

1=TODAY()   → current date (updates daily)
2=NOW()     → current date AND time

These are volatile — they recalculate every time the sheet changes. For a fixed timestamp, type the date or use Ctrl+;.

Pulling Pieces Out of a Date¶

excel

5 lines

1=YEAR(A2)      → 2026
2=MONTH(A2)     → 6
3=DAY(A2)       → 15
4=WEEKDAY(A2)   → 1–7 (day of week)
5=TEXT(A2,"ddd")→ "Mon"

Building & Shifting Dates¶

Function	Returns
`DATE(2026,6,15)`	A real date from parts
`EOMONTH(A2, 0)`	Last day of A2's month
`EOMONTH(A2, 1)`	Last day of next month
`EDATE(A2, 3)`	Same day, 3 months later
`WORKDAY(A2, 10)`	10 working days after (skips weekends)

Differences Between Dates¶

excel

4 lines

1=B2 - A2                  → number of days between
2=NETWORKDAYS(A2, B2)     → working days (excludes weekends)
3=DATEDIF(A2, B2, "Y")    → whole years between (great for age)
4=DATEDIF(A2, TODAY(),"Y")→ someone's age

DATEDIF units:  "Y" = years   "M" = months   "D" = days

Note

DATEDIF is a hidden gem — it doesn't appear in AutoComplete, but it works in every version. Perfect for age and tenure calculations.

A Deadline Tracker¶

excel

2 lines

1=IF(TODAY() > Deadline, "⚠️ Overdue",
2   IF(Deadline-TODAY()<=3, "Due soon", "On track"))

Combining TODAY() with IF (Chapter 5) builds a live status column that updates itself every day you open the file.