Raw Excel Data contains different Date formats - matlab

Question

I have huge amounts of raw data that are separated by columns. All is well when i import these to Matlab except for the fact that I just saw that the excel files contains different formats for the dates.
One series (i.e 3 days, 1 row or each hour gets 3x24 rows) have its' dates in the format "mm/dd/yyyy" which neither excel or matlab recognizes as proper dates.
I've tried solving this problem in different ways. First i tried to just highlight the cells and use the function format cells, but this didn't work since excel doesn't see them as 'cells' but rather as 'text'.
Then i tried the Text to columns function which didn't work either (delimited or fixed width).
Im really stuck and would appreciate some help with this.

Answer 1

In Excel:
If cell A1 has a string like mm/dd/yyyy then try this:
=DATE(RIGHT(A1,4), LEFT(A1,2), MID(A1,4,2))
In Matlab:
=datenum(yourDateString, 'mm/dd/yyyy')

Answer 2

Select the desired range to fix and use this script:
Sub bulk_Date_fix()
on error resume next
Set d_ranged = Selection
For Each a In d_ranged
a.Value = Split(a.Value, "/")(0) & "/" & Split(a.Value, "/")(1) & "/" & Split(a.Value, "/")(2)
Next
on error goto 0
End Sub
How it works: The above script loops through all the cells in the selected area and splits out the various attributes of a date based on the "/" symbol.

Answer 3

I examined your file and you will need to go back to the source data to straighten this out. Instead of "opening" the file in Excel, you will need to IMPORT the file. When you do that, the text import wizard will open, and you can then designate the date column as being of the format DMY (or whatever format is being generated by the source).
The problem is that there is a mismatch between the format of the file, and your Windows Regional Short date format. If you look at Row 229, you will see that real dates are present, but out of sequence with the rest.
Excel parses dates being input according to the Windows Regional Short Date settings. If the date doesn't make sense, according to that parsing (e.g. month > 12) , Excel will interpret the date as a string; if the date does make sense, it will be interpreted as a date in accordance with that windows regional date component order, and this will be different from what is intended.
So the first few hundred dates are strings, but at line 229, the date, which is probably meant to be 12 OCT 2014, gets changed to 10 DEC 2014. This will happen in other areas where that value in the 2nd position is 12 or less.
EDIT: I am not certain of the variabilities inherent in using XL on the MAC. In the Windows version of XL, the "text import" feature is on the Data Ribbon / Get External Data Tab:
When you click on that and open a text file, you will see the Text Import Wizard, and when you get to Step 3, you will be able to specify the text format of the data to be imported: