Some time ago working with dates and times was a pain for me. In several of my projects I had to calculate a person's age based on their birth date. I created a members area that allowed the administrators to set the maximum amount of time users can have a password before they must change it and remind each one how many days left before the change. I also had to create time-bomb accounts that worked for several days after its creation and then became useless.
Digging into the PHP and MySQL documentation I found and then worked with several functions that made my life easier. Now I want to share some code tips that allow better manipulation of the time and date in your projects and everyday needs.