Salaam
I have just uploaded times for 2019 in CSV format without issue, but the file only contained data (for the whole of) 2019. I already had data for 2018 including the last days for December, uploaded from last year. (One thing I used to forget was to remove the line for Feb 29 for non-leap years as the plugin checks and complains if that is included).
In the first column in the CSV file is the date, what I have done is done a “Find and Replace” on the CSV file using Notepad to change 2018- to 2019- (the extra dash is just to ensure ONLY the year is changed just in case that “2018” occurred in the times). Saved the file ensuring the CSV extension remains and uploaded that.
You could upload a 2018 csv file then 2019 csv file rather than put more then a years data in one file. In theory I think you could upload several years worth of data as long as the correct year was included in the first column. I don’t think the the plugin would stop you doing that. Though of course you may want to adjust times for each year to cater for the different dates for clocks going forward/backward and any changed Jamaat times for Ramadan.
One feature that could be useful is a “Preview” feature in the Admin area, for future months that have been uploaded. Though the plugin indicates succesful upload there doesn’t seem to be an easy way to check the data after upload for mistakes in future months, apar from waiting until that date !