PHP Time Class: Manipulate times and dates

This class can perform several types of operations to manipulate times and dates. Currently it can:

- Convert a time string into a timestamp value
- Take a timestamp value and return a string telling how it passed since that time
- Calculate the number of days or time between two dates
- Calculate the date and time adding an offset to the current date and time
- Return the name of the current season of the year.
- Return an array with all years starting 1910 and a given date
- Format a given date
- Return HTML to display a calendar of a given month and year