We handle a lot of tables with a lot of dates in the text format: DD-MM-YYYY or MM-DD-YYYY. I know I can add a date to a cell with //mm-dd-yyyy, but doing this one by one for two columns of 300+ values is kind of hard, so I'd like to know if anyone has done this, if there is a procedure to convert this:

into this:

for all the cells in those columns, of course, these are two columns from a larger table, with about 10 other columns with devices information, i.e. name, description, S/N, P/N, address, country, etc...
If it can be done when I'm pasting the table from the source, the xls file, that could also work, I just need the dates to be in that format so it's clear to everyone which date 02-04-2019 is (April 2nd or Feb 4th?) reading the table.
thanks in advance