Choosing a date and fortune telling are two completely different things, but both of them are rooted in China's traditional five lines of gossip theory.
Fortune-telling is to arrange the eight characters according to the date of birth, and use the sun to represent the fate of the Lord himself, and then look at the other seven characters and their influence on the Lord. This is the situation of the eight characters themselves, which is often called "fate." There is no good or ill luck in life itself. Only by looking at another set of eight characters composed of day, month and day, that is, the eight characters of the day, and then looking at the influence of the eight characters of this day on life itself, can we determine the good or ill luck.
Generally, what the almanac says is only the quality of the constellation itself, which has nothing to do with birthdates. Therefore, auspicious days or auspicious days in the yellow calendar are different for everyone.
There is also the monkey and the tiger you mentioned. In the zodiac, the monkey is Shen and the tiger is Yin, and they collide with each other. This is the root of the collision between the tiger and the monkey.
However, there are two different constellations between two people, not just two zodiac signs, so we can't talk about a person just by the zodiac.
However, when choosing the date, people who belong to the tiger in the zodiac will be considered unlucky and fierce if there are no other changes in meeting. Similarly, the little monkey is fierce when he meets a tiger, but the fierceness is big and small.