(2015-07-01)As a student or professional is important that you write the date correctly.
(2014-03-25)We use the past simple: For actions which happened or finished in the past. The time is either started or implied.
(2014-03-25)We use the indefinite article a/an to talk about something in general or for the first time. We use the definite article the to talk about something specific i.e. something which we mention for a second time or which is ...