My original xls spreadsheet is on a memory stick and was created in 2005. All other cells etc seem ok but the date always changes to #### when inputted.
If you meant “###” , it is a signal that the cell contents are too large to be displayed inside the cell bounds.
In that case you could make your cell wider to display the value.
HTH, lib
Make sure you actually have day / date format specified for the cell(s) in question. Excel kept track of dates as days + portions of days since Jan 01,1900 as I recall, so you could have some bizarre value of 43190.7 (or thereabouts) for January 29, 2018, or if the default kicks in it might include the calendar date as well as the time. OR, just start by making the column wide enough so you can see what is going on 
If ### is displayed instead of a numeric or date value that means the column is too narrow. Increase column width, most comfortably just by having the cell cursor in the column in question and press Shift+Alt+Right
Thanks everyone.
I investigated myself a bit more after I posted and realised that the column just needed to be formatted to ‘Date’ and all was normal after that.
I did an Excel course about 20 years ago and my inspiration must have come from there…
Good job, In that case please mark the answer from @gnezlek as Correct, by clicking on the checkmark icon at the left side of his answer.
Good job, In that case please mark the answer from @gnezlek as Correct, by clicking on the checkmark icon at the left side of his answer.