R date format when written in excel comes as general not date : I am using openxlsx package to write back a file. i have already used as.date and format function to make my fates look like dd-mmm-yyyy
but when I open the excel file, even though the date comes as, say "12-may-2018", I cannot filter them out like excel dates. it shows that the type of the data is general. even if I convert it to date format in excel, it still doesn't let me filter it out by year, month and day, which happens for excel dates. I can convert them to date type by manually palcing my cursor in the middle of a cell and pressing the return key. Doing that for the whole data will be too much manual effort which I want to reduce. Is there any way to make it happen. Thanks for any suggestions that you guys give.