Set creation date using SetFile / date formatting - shell

Question

I'd like to copy creation date from a file and apply it to the folder the file is sitting in. I'm using SetFile for this purpose. I"m getting error: Invalid date/time. My assumption is that it's the format of the date that is not working. How do I format the date properly? Could someone suggest solution? Thanks
set filesToProcess to choose folder with prompt "Select folders:" with multiple selections allowed
repeat with thisFile in filesToProcess
tell application "Finder"
try
set creationDate to creation date of (first file in the entire contents of thisFile whose name ends with "low_r.pdf")
set formattedCreationDate to --creationDate needs reformatting?
do shell script "SetFile -d " & formattedCreationDate & " " & quoted form of (POSIX path of thisFile)
on error fileNotFound
set label index of thisFile to 2
display dialog fileNotFound
end try
end tell
end repeat

Answer 1

Final working code:
set filesToProcess to choose folder with prompt "Select folders:" with multiple selections allowed
repeat with thisFile in filesToProcess
tell application "Finder"
try
set creationDate to creation date of (first file in the entire contents of thisFile whose name ends with "low_r.pdf")
set formattedCreationDate to quoted form of my stringForDate(creationDate)
set formattedFolderLocation to quoted form of (POSIX path of thisFile)
do shell script "SetFile -d " & formattedCreationDate & " " & formattedFolderLocation
on error errorMsg
set label index of thisFile to 2
--display dialog errorMsg
end try
end tell
end repeat
on stringForDate(aDate)
if aDate is "" then return null
if class of aDate is not date then return null
set {year:dYear, month:dMonth, day:dDay, hours:dHours, minutes:dMinutes, seconds:dSeconds} to aDate
set dMonth to dMonth as integer
if dMonth < 10 then set dMonth to "0" & dMonth
if dDay < 10 then set dDay to "0" & dDay
return ((dMonth & "/" & dDay & "/" & dYear & " " & dHours & ":" & dMinutes & ":" & dSeconds) as string)
end stringForDate
Thanks to everyone for contributions and #Zero for sharing the subroutine

Answer 2

Try this.
set filesToProcess to choose folder with prompt "Select folders:" with multiple selections allowed
repeat with thisFile in filesToProcess
tell application "Finder"
try
set theFileDate to (creation date of (first file in folder thisFile whose name ends with "low_r.pdf"))
set formattedCreationDate to (word 2 of short date string of theFileDate & "/" & word 1 of short date string of theFileDate & "/" & word 3 of short date string of theFileDate) & space & time string of theFileDate
--need to flip dd/mm/yyyy to be mm/dd/yyyy Ues this line -->>set formattedCreationDate to short date string of theFileDate & space & time string of theFileDate <<-- instead if your country's date format is already mm/dd/yyyy
my doCommand(formattedCreationDate, thisFile)
on error fileNotFound
set label index of thisFile to 2
display dialog fileNotFound
end try
end tell
end repeat
on doCommand(formattedCreationDate, thisFile)
do shell script "SetFile -d " & (quoted form of formattedCreationDate) & " " & quoted form of (POSIX path of thisFile)
end doCommand