What is a time stamp?
Often when you use excel to track a particular item (like expenses, exercise schedules, investments) you usually enter the current date (and time). This is nothing but timestamping. Once the item is time stamped, it is much more easier to analyze it.
So how do I generate timestamps in Excel?
We all know about the now() formula in excel and how it tells you the current date and time. The only problem with it is that, when you press F9 or recalculate formulas, the now() will be changed to reflect latest date and time. Thus we cannot use NOW() as a time stamp.
A good alternative (although manual) is to use keyboard shortcuts CTRL + ; or CTRL + : to insert current date and time in the active cell. Since this places the value, we don’t need to worry even if the date or time changes. But the only issue is, every time you need a time stamp you have to press the 2 keys.
A better way to get timestamps in excel is to use a special type of formulas, called as circular formulas.
What the heck is a circular formula?
A circular formula refers to itself (or to another cell which in turn refers to this cell). Confused ? Well, let me give you an example.
=if(A2<1000, A2+1,A2)
Now the above formula is normal, but the moment you write it in the cell A2, you have made it a circular formula. So, each time you run the formula (by pressing F9) the value in A2 will go up by 1, just like an incrementing counter.
But here is a thing you should be aware of: There is a setting called “iterations”, it tells excel how many times it should run a formula before finalizing the result.
This setting wouldn’t make any sense in case of regular formulas. But it is very important for circular formulas. If not for this, excel would go in to an infinite loop and stall.
Now, by default iterations in formula computation is turned off. That means when you write a circular formula or create a circular reference, excel shows you a message warning you and it doesn’t evaluate the formula.To turn the iterative calculation, and thus enable usage of circular formulas, go to menu > tools > options > calculation tab and check the iteration box. In excel 2007, you can go to office button > excel options > formulas > iteration area.
As you can see the default max. iterations per formula execution is 100, which means, every time you run the circular formula, excel calculates it 100 times before presenting the value. So our formula =if(A2<1000, A2+1,A2) written in cell A2 would go up by 100 every time you run.
Back to Generating Time Stamps
Now that you are knowledgeable about circular formulas, here is how we can refine the “time stamp generation” problem:
if the cell doesn’t already have time stamp, insert current date time using now(), otherwise leave the value as it is
and we will trigger the formula once we make certain changes, for eg. whenever you enter data, you can tell excel enter timestamps. See this:
The formula itself is very simple:
=IF(C3<>"",IF(B3="",NOW(),B3),"") in cell B3.
What it does?
It checks cell C3 and whenever it is not empty it runs the circular formula IF(B3="",NOW(),B3) which fetches NOW() value only if the cell B3 doesn’t already have a value, thus serving timestamps.
The above formula works only if you have enabled iterative calculation mode as described above.
Your thoughts ?
PS: Having questions on formulas, try our excel formula helper tool and learn 50+ forumals in a fun way
23 Responses to “Learn Top 10 Excel Features”
What it looks like if excel without formula?? 🙂
It would be not excel it would just be fancy tables in which you could just use power point. (Chandoo) would Access be an alternative?
Awesome piece of work!!!
Great article.
Chandoo - my biggest interest in the article was the awesome word-graphic at the top - where did you go to get it done into a shape?
@Rich.. thank you. I used http://www.tagxedo.com/ to generate this word cloud. I took all the comments in the original post, pasted them in tagxedo website and set up the shape etc.
Awesome Chandoo.. You need always needs coffee to start up with. BTW , how did u created the Heart Shaped picture filled with High Repetitive text in it .. Please put it on your Next blog ...
Chandoo, good article. I’ve added a link to it from Connexion – our collection of the most useful and interesting spreadsheet-related articles from the web. See http://www.i-nth.com/resources/connexion
Hi,
Just one small question. Where the hell have been I in the past for not discovering this website sooner?
I've lost a job interview recently where even though I had the subject knowledge, I was not upto their mark in Excel.
Thank you for all the free tips, guidance and for creating this forum environment.
[PS: I've just been through the site for the 1st time, and have signed up for the newsletter. You can expect pretty stupid questions from me soon]
Hy Chandoo, you always inspire me with to explore something new in excel. This data structure table is only for excel 2007 or compatible to 2010. I recently installed latest excel version 2013 in my System and experience problems regarding operating according to previous one. I'm waiting your article relates to that excel version.
Thanks
Awesome article Mr. Chandoo and that is a awesome heart shaped pic you created. Great tips as well.
[...] Learn Top 10 Excel Features | Chandoo.org – Learn Microsoft Excel Online. [...]
Chandoo is awesome..
Thanks, i got better, And i always get 90.50 in my grade card but now i get 96.50 i improved because of the tutorials you gave, Thank You Very Much Chandoo Guy.
Hi chandoo, i am intersted in seeing the video or step by step done procedure of analysing the comments and presenting in the data percentage steps. I think this one would be first step in finding out how generally happens data calculation. Thank you.
As well i would like to know how to get that black shape art of your face which i see in chandoo. I am interested in making it for me.
Nice to see the features considered by Excel users to be most useful. It might be a good idea to also analyze StackOverflow Excel questions to see what keywords appear most often.
Here are my top 10 Excel Features (for advanced users):
http://www.analystcave.com/excel-10-top-excel-features/
Thanks a ton for this it totally helped with my homework ????
Very good effort
Thank you for this. Lots of learning in the links you've provided for this septuagenarian.
Pls send me new post
Dude, your humor ? ?
Loved your work.
Hello Sir,
I am Sanjeev Khakre and i from Indore City, India , I am your big follower and i have watch your videos and learnt a lots of excel trick or function and many more . thanks so much for all of your excellent support.
Your excel knowledge is real awesome.
Thanks
Sanjeev
Your work is excellent but pls willing to know more details about the features of microsoft excel
Chandoo Would Access be a better alternative than VB?