Adding time stamp to digital photos

I have a Panasonic DMC-ZS3 digital camera. Its major problem is that there is no setting for it to add date-time on every photograph, you have to do it manually (what a stupid design decision!). My previous Nikon did it automatically:

The jpg file format has exif data embedded in it. Below is a jpg file opened in notepad. As you can see, it includes the date and time:

You can add the date and time to your pictures automatically in batch by using irfanview or imagemagick