Every line on your palm has a start and an end. Each line is divided into sections of 7 years. Each 7-year section helps you find out when an event happened with good accuracy.
Life line starts from the top (as shown in the picture here) and is divided into 100 years. Any cross, island, square, or other sign can be dated (as a year from birth) using a scale. If the life line is short and does not reach far down, the person may not live the full 100 years (unless a parallel, strong life line is also present).
The Destiny, or Fate, line works in reverse. It starts from the bottom of your palm and runs up to age 91. It usually crosses the head line at around age 35. So the part above the head line shows fate after age 35. The scale does not apply evenly along this line. Instead, use the scale separately above and below the head line to date events accurately.
Marriage timing is worked out from the bottom of the Mercury mount to the top of the Mercury mount, covering a span of 60 years. If a marriage line sits exactly in the middle, marriage is expected around age 30. Multiple lines show multiple deep relationships or marriages.
The Health line runs from the bottom to the top of the hand and is divided into 100 years. A scale can be used to work out the timing.
A palmist should always use a magnifying glass, a scale, and focused light on the palm, as these are essential for prediction. Without good light or a magnifying glass, important signs can be missed and the scale can be read wrongly. If a photo of the palm is used instead, software (many free options are available) should be used to detect the time milestones on the person's hand.