First some good news,
On 21st November, 2010, our little blog received its 10,000th comment!
Thank you so much for making this happen.
Those of you reading chandoo.org for a while know my penchant for comments. I have learned a lot of excel tips & ideas just by reading the comments you posted on this blog. I think comments are one of the best parts of this blog. So, naturally, I wanted to celebrate this milestone, with something big & awesome.
My intention was to download all the 10,000+ comments and play with the data to come up with something outstanding, like a dashboard. It took me 2 days to conceptualize and create this beauty.
10,007 comments visualized in an Excel Dashboard:
[click here for a larger version]
Summary of Findings from the Dashboard:
- Out of 10,007 comments, 8766 are comments left by people and 1241 are ping-backs (a comment made automatically by other blogs when they link to chandoo.org).
- Roughly 20% of comments are @ replies.
- 31 posts had more than 50 comments each. The maximum comments were 313 on the last visible cell poll.
- These 10,007 comments came from 2507 unique people. Top 20 commenters made 28% of comments.
- Median words per comment are 33. You said a total of 485,000 words so far. Impressive.
- There were only 5 days with zero comments in 2010 (as against 66 in 2008 and 15 in 2009).
- Fridays are most popular days for commenting with 20% comments coming in.
Learn How Dashboard is Constructed in a Crash Course:
I made this dashboard with lots of love & coffee. Of course, coffee wont magically turn data into in-cell charts. We need to arm twist our data and get the insights out ourselves.
That is why I made an hour long tutorial explaining how I constructed this dashboard. In the video I explain how I came up with the design, what formulas I used to cleanse & process the data, how various charts were constructed, what techniques I have used to put this together.
As this video is kind of advanced training on dashboards, I have decided to sell it. You can get a copy of the video & unlocked excel files for $37.
What you get with the purchase:
- A HD video explaining the dashboard construction process
- Same video in iPod compatible format for watching on the go.
- 2 Excel files, the original version & instructor version (unlocked)
Please note: You will not enjoy the video if you are an Excel beginner. Instead go thru Excel Dashboards page to equip yourself with necessary dashboard & charting skills before getting a training like this.
How is this Dashboard Made?
If you are curious to know which nuts & bolts are used in the dashboard, read up:
- The chart showing monthly trend of comments and day of week distribution are 2 different charts, one arranged on top of other.
- The word cloud showing relative frequencies of words used in comments is made using wordle. This is the only non-native Excel part of the dashboard.
- The Top 10 tables at the bottom are incell charts with some fancy colors.
- I have used pivot tables, SUMPRODUCT, SUMIFS, INDEX+MATCH, VLOOKUP formulas to process the data.
- Word counts are generated by processing the comment text using this technique.
Download the Dashboard File:
Click here to download a locked copy of the dashboard [mirror here]. You can examine the dashboard, but you can not alter it as it is password protected.
If you want an unlocked copy, you can get it by purchasing the video tutorial. Click here (or here).
A Big Thank You
A big, warm, cuddly thanks to you for making 10,000 comments. Everyday, your comments teach me new tricks on Excel & make me better at what I do. I am sure you feel the same about others comments.
Special thanks to top commenters – Jon Peltier (228), Hui (186), Jeff Weir (148), Robert (138), Jimmy (62), Rick Rothstein (60), Martin (58), Daniel Ferry (54), Dan l (53). Also, kudos to Stef@n for leaving a 900 word comment, the longest ever.
How do you like the dashboard?
Do you like the dashboard? Do you find it insightful? What modifications you would have made to it? Go ahead and share your ideas and tips with us. Please leave a comment.
PS: And get a copy of the training video if you work with dashboards a lot. I am sure you can pick up few tricks to become even more awesome.
14 Responses to “How many ‘Friday the 13th’s are in this year? [Formula fun + challenge]”
in C3=2016
in C4=3
in C5=1 (the first next year with three Friday the 13ths)
=SMALL(IF(MMULT(--(MOD(DATE(C3+ROW(1:1000),COLUMN(A:L),13),7)=6),ROW(1:12)^0)=C4,C3+ROW(1:1000)),C5)
formula check in the next 1000 years
This will generate a table of counts of Friday the 13th's by year. If I didn't screw it up the next year with three is 2026.
I created a simple parameter table with a start date and end date that I wanted to evaluate. That calculates the number of days and generates a list of those days. Then filter and group. The generation of the list in power query (i.e. without populating a date table in excel) is pretty cool, otherwise this isn't really doing anything than creating a big date and filtering/counting.
let
Source = List.Dates(StartDateAsDate, Days2, #duration(1,0,0,0)),
ConvertDateListToTable = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
AddDayOfMonthColumn = Table.AddColumn(ConvertDateListToTable, "DayOfMonth", each Date.Day([Column1])),
AddYearColumn = Table.AddColumn(AddDayOfMonthColumn, "Year", each Date.Year([Column1])),
AddDayOfWeekColumn = Table.AddColumn(AddYearColumn, "Day of Week", each Date.DayOfWeek([Column1])),
FilterFriday13 = Table.SelectRows(AddDayOfWeekColumn, each ([DayOfMonth] = 13) and ([Day of Week] = 5)),
Friday13thsByYear = Table.Group(FilterFriday13, {"Year"}, {{"Number of Friday the 13ths!", each Table.RowCount(_), type number}})
in
Friday13thsByYear
With the parameters replaced by values should you want to play along at home. This runs for 20 years starting on 1/1/2016.
let
Source = List.Dates(#date(2016,1,1), 7300, #duration(1,0,0,0)),
ConvertDateListToTable = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
AddDayOfMonthColumn = Table.AddColumn(ConvertDateListToTable, "DayOfMonth", each Date.Day([Column1])),
AddYearColumn = Table.AddColumn(AddDayOfMonthColumn, "Year", each Date.Year([Column1])),
AddDayOfWeekColumn = Table.AddColumn(AddYearColumn, "Day of Week", each Date.DayOfWeek([Column1])),
FilterFriday13 = Table.SelectRows(AddDayOfWeekColumn, each ([DayOfMonth] = 13) and ([Day of Week] = 5)),
Friday13thsByYear = Table.Group(FilterFriday13, {"Year"}, {{"Number of Friday the 13ths!", each Table.RowCount(_), type number}})
in
Friday13thsByYear
=MATCH(3,MMULT(N(WEEKDAY(DATE(C3+ROW(1:100)-1,COLUMN(A:L),13))=6),1^ROW(1:12)),)+C3-1
It should be pointed out that Alex's solution, unlike some others, has the additional advantage of being non-array. My solution was nearly identical but with -- and SIGN instead of N and 1^.
=C3-1+MATCH(3,MMULT(--(WEEKDAY(DATE(C3-1+ROW(1:25),COLUMN(A:L),13))=6),SIGN(ROW(1:12))),0)
Sub Friday13()
Dim StartDate As Date
Dim EndDate As Date
Dim x As Long
Dim r As Long
Range("C7:C12").ClearContents
StartDate = CDate("01/01/" & Range("C3"))
EndDate = CDate("31/12/" & Range("C3"))
r = 7
For x = StartDate To EndDate
If Day(x) = 13 And Weekday(x, vbMonday) = 5 Then
Cells(r, 3) = Month(x)
r = r + 1
End If
Next
End Sub
Calculate next year with 3 Friday 13th. Good for 100 years different from year entered in cell C3
Sub ThreeFriday13()
Dim StartDate As Date
Dim EndDate As Date
Dim x As Long
Dim WhatYear As Integer
Dim Counter As Integer
Range("E7").ClearContents
StartDate = CDate("01/01/" & Range("C3") + 1)
EndDate = CDate("31/12/" & Range("C3") + 100)
Counter = 0
For x = StartDate To EndDate
If WhatYear Year(x) Then
WhatYear = Year(x)
'Different year so reset counter
Counter = 0
End If
If Day(x) = 13 And Weekday(x, vbMonday) = 5 Then
Counter = Counter + 1
If Counter = 3 Then
WhatYear = Year(x)
Exit For
End If
End If
Next
Range("E7") = WhatYear
End Sub
*RE-POST as not equal did not show earliuer
Calculate next year with 3 Friday 13th. Good for 100 years different from year entered in cell C3
Sub ThreeFriday13()
Dim StartDate As Date
Dim EndDate As Date
Dim x As Long
Dim WhatYear As Integer
Dim Counter As Integer
Range("E7").ClearContents
StartDate = CDate("01/01/" & Range("C3") + 1)
EndDate = CDate("31/12/" & Range("C3") + 100)
Counter = 0
For x = StartDate To EndDate
If WhatYear NE Year(x) Then
WhatYear = Year(x)
'Different year so reset counter
Counter = 0
End If
If Day(x) = 13 And Weekday(x, vbMonday) = 5 Then
Counter = Counter + 1
If Counter = 3 Then
WhatYear = Year(x)
Exit For
End If
End If
Next
Range("E7") = WhatYear
End Sub
earlier*
I've a doubt with using array formula here.
In sample workbook, I tried to replicate the formula again.
=IFERROR(SMALL(IF(WEEKDAY(DATE($C$3,ROW($A$1:$A$12),13))=6,ROW($A$1:$A$12)),$B7),"")
For this I selected C7 to C12, and typed the same formula and pressed ctrl+alt+Enter. But in all cells it is taking $B7 (and not $B7, $B8, $B9.... etc)
and since it is array formula I can't edit individual cell.
Please guide.
Thanks
Hi Chandoo,
Cool stuff. You need to clarify that the answer of 5 represents the 1st month in the year that has a Friday the 13th, and not the number of Fridays the 13th in the year. Subtle, but important difference.
Thanks,
Pablo
I like the MMULT() function far more, but here's how I would have tackled it. It uses an EDATE() base and MODE() over 100 years. I'm assuming that 100 years is enough time to catch the next year with 3 friday 13th's. Array entered, of course.
{=MODE(IFERROR(YEAR(IF((WEEKDAY(EDATE(DATE(C3, 1, 13), ROW(INDIRECT("1:1200"))))=6), EDATE(DATE(C3, 1, 13), ROW(INDIRECT("1:1200"))), "")), ""))}
Finding all the Friday the 13ths in a Year:
=SUMPRODUCT((DAY(ROW(INDIRECT(DATE(C3,1,1)&":"&DATE(C3,12,31))))=13)*(TEXT(ROW(INDIRECT(DATE(C3,1,1)&":"&DATE(C3,12,31))),"ddd")="Fri"))
{=sum(if(day.of.week(DATe($YEAR;{1;2;3;4;5;6;7;8;9;10;11;12};13);1)=6;1;0))}
just list the years