added timeDelta calculation.
Revert "added timeDelta calculation."

This reverts commit 155c0eb0b24148afea4d8ffee62d2c833eabc016.
added timedelta calculation.
refactored code block into function __get_locators().
renamed var timeDelta into period.
added function __hours_locators to handle all periods < 1 day.
fully implemented function __hour_locators()
added __day_locators() and fixed variable naming.
Fixes #2