The Live Clock: Excel Formulas TODAY() and NOW() Explained

Keep your spreadsheets current, calculate deadlines, and track durations automatically.

Welcome! In the world of data analysis, timeliness is everything. An Excel report generated today needs today's date, and a transaction log needs the precise time it was created. Manually typing these values is a waste of time and a source of error. Excel provides two simple, yet incredibly powerful, functions to handle dynamic date and time entry: **TODAY()** and **NOW()**. These are the keystones of any automated dashboard, aging report, or deadline tracker.

Phase 1: Understanding the Core Difference: Date vs. Date & Time

Both functions return a constantly updating value, but their scope is different:

• =TODAY(): Returns only the current date (e.g., 2025-09-30). It is represented by a whole number in Excel's serial date system.
• =NOW(): Returns the current date and the current time (e.g., 2025-09-30 20:42:29). It is represented by a serial number with a decimal component (the decimal represents the time).

Crucial Concept: Volatility. Both TODAY() and NOW() are **volatile functions**. This means they recalculate (update their value) every time the workbook is opened or a change is made to any cell in the worksheet. They do not update every second like a real clock, but rather on any calculation event.

Phase 2: Practical Applications of TODAY()

The TODAY() function is invaluable for time-based comparisons and reporting.

1. Calculating Age or Seniority (Years/Days)

If you have a start date (e.g., cell A2) and want to know the number of days passed, the formula is simply subtraction, as dates are just numbers:

=TODAY() - A2  
// Result is the number of days passed.
            

To convert this to years, simply divide by 365.25 (to account for leap years):

=(TODAY() - A2) / 365.25 
            

2. Dynamic Overdue/Due Status

You can use TODAY() within an IF statement to create a self-updating status column for projects or invoices (where B2 is the Due Date):

=IF(B2 < TODAY(), "OVERDUE", IF(B2 = TODAY(), "DUE TODAY", "Upcoming"))
            

3. Projecting Future Dates

Easily determine a date 90 days from now:

=TODAY() + 90 
            

Advanced Tip: For more robust business-day calculations, combine TODAY() with the **WORKDAY** or **NETWORKDAYS** functions to exclude weekends and holidays.

Phase 3: Leveraging NOW() for Timestamping and Time Differences

The NOW() function is crucial when you need to track the exact moment an action occurred or how much time elapsed.

1. The Live Timestamp Tracker

Place =NOW() in a prominent cell of your dashboard. Every time the sheet recalculates, this cell updates, giving you a clear indicator of the data's freshness. Make sure to format the cell to display both date and time (Format Cells -> Custom -> dd/mm/yyyy hh:mm:ss).

2. Calculating Time Duration/SLA

If you have a Start Time (C2, e.g., 8:00 AM) and you enter =NOW() in the End Time cell (D2), the difference =D2 - C2 will return the duration. You must format this result cell as a Time or Custom format (e.g., [h]:mm:ss) to see the hours/minutes/seconds.

3. Freezing a Static Timestamp (The Efficiency Hack)

Since NOW() is volatile, it’s not ideal for recording a permanent timestamp (like the time an order was placed). The best efficiency hack is to use the keyboard shortcut to insert a static, non-updating time:

• Static Date: Press **Ctrl + ;** (Control and semicolon).
• Static Time: Press **Ctrl + Shift + ;** (Control, Shift, and semicolon).

By mastering the dynamic nature of TODAY() and NOW(), and knowing when to use their static counterparts, you move from manual data entry to creating self-sustaining, analytical spreadsheets that manage time for you.

Master more time-saving Excel formulas and shortcuts with our tutorials!