Formulas no longer working with date format

Evening everyone,

I'll jump straight into my problem

Background

The company I work for has changed their reporting tool. This has changed the way data is presented in databases and also how data looks after being exported to Excel.

Issue

I used to export time stamps from our database to Excel, in the following format (yyyy/mm/dd hh:mm)

From those time stamps I had the following working formulas for:

1. Turning a date into an ISO week

=IFERROR(INT((X366-DATE(YEAR(X366-WEEKDAY(X366-1)+4),1,3)+WEEKDAY(DATE(YEAR(X366-WEEKDAY(X366-1)+4),1,3))+5)/7),"Not Resolved")

Where column X is the date

2. Calculating how many hours an issue took to resolve, after being reported (ignoring weekends)

=IF(WEEKDAY(W366,2)>=6,X366-(INT(W366+8-WEEKDAY(W366,2))+0.25),X366-W366)

Where column W is the reported date, and column X is the resolved date

3. Turning a date into an mmmm/yy string

=TEXT(X366, "mmmm/yy")

Where X is the date.
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Now I have to export time-stamps in the following format dd/mm/yyyy hh:mm (12 hour clock) and none of the above formulas work anymore.

Question

How do I get these formulas to work with the new format? i.e. what is it about the change that has screwed ALL my functions?

Refer to the spreadsheet attached in my second post. The one attached in the original post is not the proper file

-> Green highlight shows formulas working with old time-stamp format.
-> Red highlight shows formulas failing with new time-stamp format.

i dont see any green or red cells, could you be more specific as to where i am looking?

Try these formulas:

AB - =WEEKNUM(DATEVALUE(LEFT(X368,FIND(" ",X368))))
AD - =TEXT(DATEVALUE(LEFT(W368,FIND(" ",W368))), "mmmm/yy")
AE - =TEXT(DATEVALUE(LEFT(X368,FIND(" ",X368))), "mmmm/yy")
AF - =DATEVALUE(LEFT(X368,FIND(" ",X368)))+TIMEVALUE(TRIM(RIGHT(W368,8)))-DATEVALUE(LEFT(W368,FIND(" ",W368)))+TIMEVALUE(TRIM(RIGHT(W368,8)))

they are working for me, unless i am missing the objective... have alook at the attached.

sounds good, thank you for the update.