Check if two ranges of dates overlap [Excel Formulas]

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Check if two ranges of dates overlap using excel formulasWhile preparing a project plan, I had a strange problem. I wanted to highlight all the project tasks that fall with-in a certain date range. At the lowest level, the problem is like this:

There are 2 ranges of dates (a,b) and (x,y) and I want to know if they overlap (ie at least one date common between a,b and x,y)

The formula for testing such a thing seemed tricky at first. So I drew the conditions on paper to get clarity on what we should test. Evidently, there are 4 ways in dates (a,b) can overlap with dates (x,y) as shown below:

Conditions to check if two sets of dates overlap

Now, we can test for the overlap condition using a formula like this:

If x is between a and b
or a is between x and y
then overlap
else do not overlap

As you know, there is no formula in excel like isbetween(). So we have to break it up to 2 conditions and an AND() Formula. Finally the formula becomes,

=if(or(and(x>=a,x<=b),and(a>=x,a<=y)),"Overlap","Do not overlap")

Now, it seemed like quite a big formula for testing if 2 ranges of dates overlap.

So, I continued my quest for even shorter formula.

After sometime, I realized that if we test for non-overlap instead of overlap, we can write a shorter formula.

Do not understand? Let me explain.

While there are 4 ways in which (a,b) can overlap with (x,y), there are only two ways in which (a,b) cannot overlap with (x,y). See this to understand:

Conditions to check if two sets of dates do NOT overlap

Now, testing above conditions is very straight forward in excel.

the formula becomes, =if(or(y<a,b<x),"Do not overlap","Overlap")

The formula is much shorter and easy to maintain.

I was able to use it to test if a set of tasks in the project plan are running between given dates (for eg. next week). All is well in the end.

How do you test overlap conditions?

Do you ever have to test overlap conditions? What kind of formulas have you used? Please share your formula tips & tricks using comments.

Further Learning:

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20 Responses to “Untrimmable Spaces – Excel Formula”

  1. MF says:

    Hi Chandoo,
    First of all, HAPPY NEW YEAR!!! Wish you and your family another fruitful year ahead.

    To answer your question: Power Query is the best way to trim. 🙂

    Btw, if Power Query is not available, then formula would absolutely do... but did you forget to mention also Char 32?

    One more question: Is the trailing minus meant to be a negative number? Maybe only the sender knows... 🙂

    Cheers,

  2. Duncan Williamson says:

    I know these spaces can be a real pain but these days I advise Excel users to learn and use Flash Fill and that will learn what to do pretty quickly.

  3. David Hager says:

    Highlight range to be cleaned. Then, in Replace, hold down the Alt key and type 0160. Replace with nothing.

  4. Steve Jones says:

    I accomplished this by writing a macro to go through all the possible unprintable characters. Looped through the range.

  5. Ramnath D says:

    I use a different method here. First, I will copy the data from Excel and paste it in a notepad. In Notepad, I will do a Find Blanks (Space " ") and Replace (Empty) with nothing.

    Then you can copy the data from Notepad and paste it back to Excel which will be a perfect number as you desire.

    But Thanks for the formula. Its probably the 2nd out of 8 tricks as Chandoo mentioned. Waiting for the rest among 8 from other users 🙂

  6. Andrew says:

    I don't understand the x's. Why weren't they removed in the formula? Or are they part of some sort of numeric formatting that I'm not familiar with? I saw how you handled the non-breaking spaces and the dashes, but am confused about what role the x's played in all this.

    Thanks!

    • NARAYAN says:

      Hi Andrew ,

      The xs have been used solely to demarcate the actual data text ; thus , without the x in place at the end of text , as in :

      x 4,124,500.00 x

      it would be impossible to know that there are unwanted trailing characters , in this case , after the last 0.

      These xs are not part of the original data text , nor are they used in the formulae ; they are put in only so that readers can visualize the individual items of data as they are in practice. Think of them as imaginary delimiters.

      • Andrew Patceg says:

        Oh, that makes sense! Thank you for the explanation. I had a feeling it was something along those lines.

  7. Mucio says:

    You can type this character using the Keys Alt+0160.
    Very useful to replace this Character using Find and Select resource.

  8. Neva says:

    For many years, my jobs have included ETL tasks and I built this macro to help long, long ago. I tweak it every now and again. Many co-workers, past and present, have it wired to a button on their toolbar.

    Sub Clean_and_Trim()
    'CAUTION: Strips leading zeroes -- do not use on zipcodes, etc.

    If Application.Calculation = xlCalculationAutomatic Then
    Application.Calculation = xlCalculationManual
    Revert = 1
    ElseIf Application.Calculation = xlCalculationManual Then
    Revert = 0
    End If

    For Each Cell In Selection
    For x = Len(Cell.Value) To 1 Step -1
    If Asc(Mid(Cell.Value, x, 1)) = 160 Then
    Cell.Replace What:=Chr(160), Replacement:=" ", LookAt:=xlPart, MatchCase:=True
    End If
    If Asc(Mid(Cell.Value, x, 1)) = 32 Then
    Cell.Replace What:=Chr(32), Replacement:=" ", LookAt:=xlPart, MatchCase:=True
    End If
    Next x
    If Cell.Value "" Then
    Cell.Value = Application.Clean(Application.Trim(Cell.Value))
    End If
    Next

    If Revert = 1 Then
    Application.Calculation = xlCalculationAutomatic
    ElseIf Revert = 0 Then
    Application.Calculation = xlCalculationManual
    End If

    End Sub

  9. Brigitte Calahate says:

    This is awesome! What if you have several characters you need to have removed? What would be the easiest way as I can imagine there are several ways.?

    # - 35
    $ - 36
    - 62
    / - 47
    , - 44
    . - 46
    " - 34
    : - 58

  10. Roby says:

    This is typical case of a Fitbit data export to Csv file. Each number has CHAR160 as thousand separator.. how smart Fitbit, thank you 😉

    By the way, i prefer to copy the character, and use find and replace.

  11. Suhas Shetty says:

    Sometimes it happens if you copy a table from outlook and paste it in excel. When you apply formula on those cells you will get error. What i use to do is
    copy one character that looks like space,
    select the entire range,
    go to Find and replace,
    Paste the copied character in Find option
    Leave the replace option unfilled..
    click on replace all..

    All the errors shall be converted in to proper values..

    Process looks lengthier.. but it is one of the simplest method

  12. Gerry says:

    If Clean, Trim, and Substitute, or Find and Replace does not complete the job, I usually enter a value of 1 in an empty cell. Copy the Value of 1, Highlight the range of text numbers, and Paste Special, Values, Multiply. This site is great!

  13. king faisal says:

    You can use Dose for Excel Add-In that can quickly clean huge data with one click besides more than +100 new functions and features to add to your Excel to save time and effort.

    https://www.zbrainsoft.com

  14. R.Ranjit says:

    Hi,
    I have a problem in excel. The sheet attached herewith.

    TABLE CONFIG 2/6
    A B C D E F G H
    1 WEIGHT1 43,599 WEIGH2 62500 WEIGHT3 77000 WEIGHT4 66,500
    2 DEDUCTION1 15,000 DEDUCTION1 15,000 TEMP 0 DEDUCTION2 11,005
    3 RESULT 58,599 RESULT-1 77,500 RESULT-2 77,000 RESULT-3 77,505
    4 RESULT SUBSTRACT 0 0 0
    5 REQUIRED VALUE 77,500 77,000 77,505

    Note: 1- RESULT (58599) IS TO BE DEDUCTION EITHER FROM D4 OR F4 OR H4 WHICHEVER IS MOST
    LEAST CELL AMONG RESULT-1 OR RESULT-2 OR RESULT 3.
    2-HENCE, RESULT VALUE $B$3 IS TO BE PRESENTED ON CELL EITHER D4 OR F4 OR H4 WHICHER IS
    MOST LEAST VALUE
    3-FORMULA =IF(E8<H8,$B$9,IF(E8<J8,$B$9,IF(H8<J8,$B$9,IF(H8<E8,$B$9,IF(J8<H8,$B$9))))))
    CREATED ON CELL D4,F4 & H4 DID NOT WORK.
    PLS FOR YOUR HELP.
    THANK YOU

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