Sign

The twelve signs used In Tibetan astrology are: Mouse, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Sheep, Monkey, Rooster, Dog and Pig.
As there are 5 elements and 12 signs it is easy understandable that there are 60 combinations.
The elements are each used twice when the signs change.
E.g. Wood - Mouse, Wood - Ox, Fire - Tiger, Fire - Rabbit, etc.
Although the Tibetan cycle 1 start in the year 1027 the Chinese cycle 62 which starts in 1024 is used for the calculations.
But there exists also a connection with the nine mewas which start in 1024 with Green 4, followed by Blue 3, Black 2, White 1, etc. and so it takes three cycles ( lower, middle and upper cycle of 60 years) totalling 180 years for a full cycle to complete. So for the mewa's it is important to know which cycle is used.
The even years are male and the odd years are female.