Converting Text Month, General Year and Day formats to recognizable date fields

I have a large amount of data exported from a SQL database. For analytic purpose in another report it is pulled with a column for Month, Year and Day. I use the DateValue function and concatenate to put them together in a standard date format that is actionable in other reports.
I have tried the Date and Year functions to pull the information back out of the output from DateValue in a format that excel and PowerBI recognize as month and year but I am not getting proper results. I have tried formatting the columns with custom formats of YYYY, MMMM, DD but that doesn't seem to work.
I am attaching a small sample of the data for reference. The SQL output gives me columns A, B, C. I put them together in standard date in column D. I would like to keep the same discreet data that is in A, B, C but have the month, year and day recognized as date values.

load A,B,C range to PowerQuery (PowerBI)
select columns in order: Year, Month, Day
Merge columns with custom delimiter: /
change format to Date

it will give you a date in your local format defined by the system
if you want another format try : Using locale

locale.jpg

Not sure I follow what you want:

in D2

=DATE(B2,MONTH(A2&0),C2)

will give a standard Excel date

To get YEAR

=YEAR(D2)

Similar for Month and Day

to convert A2 to numeric Month

=MONTH(A2&0)