Hours (时辰 shíchen) within the Four Pillars of Destiny represent the final and most personal pillar. The secret animal is thought to be a person’s truest representation, since this animal is determined by the smallest denomination. It is used by fortune tellers that use the Four Pillars as the pillar representing information about one's kids or late age.
The hours are represented by the helpful 12 Earthly branches (and the same animal mnemonic as years, months and days within the four pillars) which were determined by Chinese scholars who charted the orbit of Jupiter. The Earthly branches also determine the calendar and compass points.
• 23:00–01:00: 子 rat
• 01:00–03:00: 丑 ox
• 03:00–05:00: 寅 tiger
• 05:00–07:00: 卯 rabbit
• 07:00–09:00: 辰 dragon
• 09:00–11:00: 巳 snake
• 11:00–13:00: 午 horse
• 13:00–15:00: 未 ram
• 15:00–17:00: 申 monkey
• 17:00–19:00: 酉 rooster
• 19:00–21:00: 戌 dog
• 21:00–23:00: 亥 pig
What is your secret animal? And what does it mean to you?
Within the Four Pillars, the month (本月 běnyuè) that you are born is the pillar that represents information about the person's parents or later years in life. Many Chinese astrologers consider the month pillar to be the most important pillar in determining the circumstances of one's adult life.
The Gregorian (Western) calendar is used for day to day activities in most of East Asia, but the Chinese calendar is still used for marking traditional East Asian holidays such as the Chinese New Year (or Spring Festival (春節).
Solar Terms (节气 jiéqi) are based on seasonal markers and make up the Chinese agricultural calendar. This table shows the correlation between the Western calendar and the Chinese months. It also shows which animals (mnemonic) belong to each astrological month giving the second of the four pillars in Chinese astrology and fortune telling.
I had trouble making this table in html, but if you click the image, you can download the pdf with the full table.

