I've got a new camera and I forgot to update the date. Consequently, the first photos are taken on 01/01/2017 instead of 04/03/2018. Given that more than 100 photos were taken, it would be a pain to change them one by one. So, here are the steps I did update the date:
Download exiv2. Just search for exiv2-0.26-msvc.tar.gz (0.26 was the most recent at the moment of writing).
Open it and extract the relevant folder (\dist\2015\x64\dll\Release in my case) in a convenient place (e.g.
Open a command prompt to the folder where you have the pictures
C:\EXIV2\bin\exiv2 -Y 1 -O 2 -D 3 ad *.jpg
The command says adjust +1 year +2 months and +3 days tothe currently stored date of the photo.
Bonus: You can also add a copyright note:
C:\EXIV2\bin\exiv2 -M"set Exif.Image.Copyright Copyright (c) 2018 Laur Ivan" *.JPG
Another bonus: exiv2 has verious bindings (e.g. python) which make various updates quite interesting.