The Ethiopian calendar is based on the Julian calendar, which is acurately behind 7 years behind the European or Gregorian calendar.
The Ethiopian day begins at dawn and not midnight as is the case in most other countries. 
One 0'clock ET is seven 0'clock international
12 Noon  ET is 6 0'clock, 4PM  ET is 10 PM etc. 
Quick Facts:
The Orthodox calendar has 365 days (366 leap year). It is divided into 13 months, 12 of 30 days each and an intercalary month at the end of the year of 5 (6 days in a leap year). 

The year starts on 01 Sept. (11 Sept. European Gregorian Calendar) in the Julian Calendar or on the12th in the year before (Julian) Leap Years. The Orthodox Leap Year follows the same rules as the Gregorian so that the extra month always has 6 days in the year before a Gregorian Leap Year. 
       Each year is named after one of the four Evangelists   
           ~   Matthew, St, Mark, St. Luke and St. John  ~
       (The extra day in a leap year is added to the year of St. Luke.)

The day of the New Year is called Kidus Yohannes (St. John the Baptist) This is because St. John was the last of the prophets and is considered a bridge between the Old and the New Testaments. 
he transfered the Gospel from the Old Testament to the New Testaments and the newness of life and salvation.
The names of the months and their starting dates are as follows:

Orthodox Month Name / Start Date   / Start Date Leap Year 
01.  Maskaram . . . . . . . . . 11 Sept.  . . . . . .  12 Sept.
02.  Teqemt . . . . . . . . . . .  12 Oct.  . . . . . .   12 Oct.
03.  Hedar . . . . . . . . . . . .  10 Nov .  . . . . . .  11 Nov
04.  Tahas . . . . . . . . . . . . .10  Dec . . . . . .   11 Dec  
05.  Ter . . . . . . . . . . . . . .   09 Jan . . . . . . .  10 Jan 
06   Yekatit . . . . . . . . . . . . 08  Feb . . . . . . . 09 Feb 
07.  Megabit . . . . . . . . . . . 10 Mar - 
08.  Miyazya . . . . . . . . . . . 09 Apr - 
09.  Genbot . . . . . . . . . . . . 09 May - 
10.  Sene . . . . . . . . . . . . . .08 Jun - 
11.  Hamie  . . . . . . . . . . . . 08 Jul - 
12.  Nahase . . . . . . . . . . .  07 Aug - 
13.  Paguemen . . . . . . . . .  06 Sep  -  
Ethiopian Week Day Name  /    English Name

Ehud,Sanbete, Krestiyan . . . . . . .  Sunday
Sagna . . . . . . . . . . . . . . . . . . . .   Monday
Maksegno . . . . . . . . . . . . . . . . . . Tuesday
Rabue  . . . . . . . . . . . . . . . . . . . .  Wednesday
Hemus . . . . . . . . . . . . . . . . . . . .  Thursday
Arbe . . . . . . . . . . . . . . . . . . . . . .  Friday
Kdamie . . . . . . . . . . . . . . . . . . . .  S