Date and Time Format
These are based on the ISO 8601 standard. Details of this format are available online, and the date/time functions in your language of choice should be able to output dates and times in this way with no problem.
Broadly speaking, dates are specified as YYYY-MM-DD while dates while times are specified as YYYY-MM-DDTHH:MM:SSZ.
Date
2014-10-01
Datetime
2015-01-22T10:44:35Z