Manipulation and sorting of date strings, location Australia

Use the the syntax where you specify the order:

DateObject[{"06.02.97",{"Day","Month","YearShort"}}]

DateObject[{1997, 2, 6, 0, 0, 0.}, "Instant", "Gregorian", -7.]


Since I couldn't find the elegant solution @Carl Woll did, how about this?

Quiet@DateObject@StringReplace[
 "06.02.97",
 day__ ~~ "." ~~ mon__ ~~ "." ~~ yr__ :> mon <> "." <> day <> "." <> yr
]

DateObject[{1997, 2, 6}]

It does throw the warning

DateObject::ambig: "Warning: the interpretation of the string 02.06.97 as a date is ambiguous."

but since you know this is what you want, then you can use the Quiet.

As for your second question, in general you could do

DateObject /@ listofdatestrings

but if all of the date strings are in the day.month.year format as above, then you could use

DateObject /@ StringReplace[
 listofdatestrings,
 day__ ~~ "." ~~ mon__ ~~ "." ~~ yr__ :> mon <> "." <> day <> "." <> yr
] // Quiet

For example

DateObject /@ StringReplace[
 {"06.02.97", "30.08.90"}, 
 day__ ~~ "." ~~ mon__ ~~ "." ~~ yr__ :> mon <> "." <> day <> "." <> yr
] // Quiet

{DateObject[{1997, 2, 6}], DateObject[{1990, 8, 30}]}