After adding a photo to a footprint, you will find two little indicators "Date" and "Location" on top of the photo thumbnail. These indicators show if a photo has a date and a location. The indicator are not shown, if photo does not have this meta information.
Simply tap the photo and choose the option Use photo location or Use photo date. The footprint will then automatically use the date and location of the photo.
This is especially helpful when adding past footprints, no matter if they are a day or a few years in the past.