Here is a familiar problem:
You create a workbook to track some data. You ask your staff to fill up the data. Almost all the input data is fine, except the date column. Every one types dates in their own format.
Here is a fun, simple & powerful way to warn your users when they enter wrong dates.
Use conditional formatting
Here is a quick demo:

How to ensure cleaner dates with conditional formatting?
- Let’s say your users need to enter date input in cell C3.
- Select C3 and go to Home > Conditional Formatting > New Rule
- Select the rule type as “Use a formula…”
- Use a formula like this: =ISERROR(DAY($C$3))
- Set up formatting to highlight incorrect dates
- Done
Explanation for the formula:
We will assume that C3 contains a valid date and try to do some sort of date operation on it, like finding the day of month using DAY($C$3). If this returns an error, that means we have an invalid date.
So to check the error status, we use ISERROR().
A caveat: dates are numbers
Since Excel dates are numbers, technically, your users can type a number in C3 (like 7) and our conditional formatting won’t trigger the error.
Bonus tip: Adding conditional formatting to an entire column
To add conditional formatting to an entire column,
- Let’s say the date inputs go to column C, starting with C3 as first input
- Select all the cells in column C that will have dates
- Set up the conditional formatting with below rule:
- =ISERROR(DAY($C3))
Download example workbook
Click here to download a simple example workbook with this technique. Examine the conditional formatting in C3 & D3 to learn more.
Do you use CF to nudge your users in right direction?
Excel Conditional Formatting is one of my all time favourite features. I use liberal amounts of CF on all my Excel recipes. I think CF makes a great ingredient if you are collecting user inputs.
What about you? Do you use conditional formatting to make sure your inputs are clean? What techniques do you use? Please share your thoughts and tips in the comments area.
Here are few more awesome ways to use conditional formatting:












11 Responses
Ciao Hui,
Collecting Excel tricks under the title “Notable Excel Websites (Non-MVP) Edition” is a brilliant idea…
Thank you in the name of all The FrankensTeam.
On our site there is a box with a picture and text highlighting:
This is a no-MVP site
we think ourselves “bad boys” a bit 🙂
For those who would like to know why our site is a no-MVP site, enough to click on the link:
http://goo.gl/lxDszY
Thank you again!
Thanks a lot
I really enjoyed this (newsletter). I must admit that I rarely read an Excel newsletter (and I subscribe to quite a few) all the way though, but this grabbed my attention and before I realized it, I was engrossed in it. I must also admit that most of this I don’t understand, yet. But, it excites me when I do learn something new in Excel. I can’t wait to see how much of this I can implement into my (constantly-evolving) ‘House Budget’ & ‘Family Medical’ worksheets that I have developed over the past few years! I sure hope to see more of these type of newsletters in the future! Thanks!
Thanks for doing this Hui! I appreciate being included.
I like Tom’s tip a lot. I posted about a tool I wrote to automate this at http://yoursumbuddy.com/tables-edit-query-dialog/
EXCELLENT !
Hui, This post is Superb! More over I have always been a fan of Roberto’s work and have learnt a lot from him.
Here are some of my recent contributions
1. Customising markers in a chart – http://www.goodly.co.in/customize-markers-in-a-chart/
2. Charting Hacks to work faster – http://www.goodly.co.in/5-charting-hacks-to-help-you-work-faster/
3. 7 Date formulas to make life easy – http://www.goodly.co.in/date-formulas-in-excel/
4. Customised scrollbar using VBA – http://www.goodly.co.in/customized-scroll-bar-in-excel/
5. Adding Direct Legends – http://www.goodly.co.in/customized-scroll-bar-in-excel/
Hope everyone enjoys!
I like the Excel Ninja Menus.
1. Select a cell or range then move till the 4-way cross appears. Right-Click and drag the selection to another place in the worksheet then, like a ninja, a menu full of skills and throwing stars pops up allowing me to do all kinds of awesomeness.
2. When you click the fill box on a Date and right click and drag it down, a lot of amazing Date options pop up.
I also brand my Excel to remind myself that I’m awesome. In my personal macro workbook I place the following code.
Private Sub Workbook_Open()
Application.Caption = “SuperKrishna’s Awesomeness”
End Sub
My favorite tip goes along with #17. If you try to copy subtotaled data (and in earlier Excel versions filtered data),when you paste it all the data displays instead of just the summarized data.
To get around this, select your summarized data, click on Find and Select tab and then select Go to Special. Click Visible cells Only and click OK. Now paste and you will see that only the summarized data has been copied.
You can also go CTRL+G and then click the Special icon at the bottom of the dialog box.
What a great idea, Chandoo! I’d love to be included in your next edition:) Perhaps a VBA exclusive version?
@Ryan
I will review this concept about 6 months out from the original post and be sure to keep your site in mind
Hui…
That sounds great, Hui:) I just realized I gave credit to Chandoo for the idea and I should have attributed it to you.
Sorry about that!