I have a lot of time series data, which includes date, time, latitude, longitude. Each date (dd/mm/yy) should have 15 time cells next to it, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 0000, 0100, 0200, 0300, 0400, 0500, 0600, 0700. However, when the data was entered if there was no latitude or longitude entered, the row was skipped, and as such there are "holes" in the data. I would like therefore to enter a line where each row is missing so that ever day records the times given above, and N/A is inputted where no latitude or longitude was recorded. Any ideas?