VBA Date cleanup / reformatting - excel

Question

I'm relatively new to VBA coding and wanted to get some ideas as to how I could do some data cleanup/reformatting. I have a excel data export from a system that has very little business logic/validation.
As a result I have a Date column that has data integrity issues that I have examples of below. Dates are not formatted the same consistently, there is dates combined with text strings, in some cases only text (in the date field)
Here are examples of the data I have in the Date column:
2/2/2018
8/3/2018
1996
1990-1991
02/29/95
1992-93
05/08/200
DECLINED
5/1418
8/14/2018
06/09/200
1/12/94, DECLINED CONTRACT 12/01/00
EXP CAT I
06/14/23018
1996
5-1-1207/07/92
8/3/2018
3-10-
1996
02/27/187
1-29-14
2/2/2018
1-4-11
3.8.99
2-17-12
10-6-16
I would like to convert the dates into the MM/DD/YYYY format. I realize where I just have pure text (e.g. 'DECLINED') that there is no way to extract a date, however I'm hoping for the other examples it may be possible to format the date to the above.
Some of the dates are plain no good (e.g. '5/1418' can't determine how to translate this), but I'm hoping for at least the dates formatted with MM-DD-YYYY and MM.DD.YYYY and similar combinations there is a way to convert their formatting, as well as where I just have 1 digit Month and Day (e.g. 2/2/2018 should be 02/02/2018). If just a 4 digit year is provided I want to convert to '01/01/(year)' Any ideas are appreciated.

Answer 1

This is one of those problems that you could spend a year trying to solve to get a 100% solution. The good news is you can get super lazy and have a nice 60% solution by using the VBA CDATE() function which makes a good guess for whatever you feed it. Tossing Split() at it to peel off extra words and whatnot (that may follow the date with a space or a comma) you can get most of the actual dates covered here. The remaining records are either dates that are so badly formatted that you will have to write code for the edge case, or it's just garbage non-date stuff you can ignore.
Create a new module in VBA and pop this in:
Public Function dateguesser(inDate As String) As Date
dateguesser = CDate(Split(Split(inDate, " ")(0), ",")(0))
End Function
Then in your sheet you can use this as a new function
=dateguesser(A1)
And copy down. For your list, you get the following:
+----+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| | A | B |
+----+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | 2/2/2018 | 2/2/2018 |
| 2 | 8/3/2018 | 8/3/2018 |
| 3 | 1996 | 6/18/1905 |
| 4 | 1990-1991 | #VALUE! |
| 5 | 02/29/95 | #VALUE! |
| 6 | 1992-93 | #VALUE! |
| 7 | 05/08/200 | ############################################################################################################################################################################################################################################################### |
| 8 | DECLINED | #VALUE! |
| 9 | 5/1418 | ############################################################################################################################################################################################################################################################### |
| 10 | 8/14/2018 | 8/14/2018 |
| 11 | 06/09/200 | ############################################################################################################################################################################################################################################################### |
| 12 | 1/12/94, DECLINED CONTRACT 12/01/00 | 1/12/1994 |
| 13 | EXP CAT I | #VALUE! |
| 14 | 06/14/23018 | #VALUE! |
| 15 | 1996 | 6/18/1905 |
| 16 | 5-1-1207/07/92 | #VALUE! |
| 17 | 8/3/2018 | 8/3/2018 |
| 18 | 3-10- | #VALUE! |
| 19 | 1996 | 6/18/1905 |
| 20 | 02/27/187 | ############################################################################################################################################################################################################################################################### |
| 21 | 1-29-14 | 1/29/2014 |
| 22 | 2/2/2018 | 2/2/2018 |
| 23 | 1-4-11 | 1/4/2011 |
| 24 | 3.8.99 | #VALUE! |
| 25 | 2-17-12 | 2/17/2012 |
| 26 | 10-6-16 | 10/6/2016 |
+----+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Clearly this is just a starting point, but I think it's a good solid starting point. The remaining crap you can start writing edge cases for in your VBA, but the closer you get to 100% the longer it's going to take to get any further and before you know it you'll be a month into this and wondering what's happened to your life.