The Lo Shu Grid places the digits of your date of birth into a fixed 3x3 magic square whose every row, column and diagonal adds up to 15. This calculator writes your date as DD/MM/YYYY, drops each non-zero digit into its own cell, and reports which numbers are present, which repeat, which are missing, and which of the eight complete lines - the arrows or planes - your date fills or leaves empty.
The Lo Shu Grid is an ancient 3x3 magic square in which each row, column and diagonal totals 15. Every cell holds a fixed number, running from 1 in the bottom-middle to 9 in the top-middle.
To build your grid, each non-zero digit of your date of birth is dropped into its matching cell. Repeated digits stack up in the same cell, so a strongly repeated number becomes an area of pronounced strength, while a number you have none of leaves its cell blank.
Each complete line through the grid is called an arrow or plane. When all three of its numbers are present in your date of birth it forms an arrow of strength; when all three are absent it is an arrow of weakness, pointing to an area to work on. There are eight such lines in total: three rows, three columns and two diagonals.
An arrow forms only when a line is wholly present or wholly absent; a line holding one or two of its three numbers forms neither. Because a date supplies at most eight non-zero digits, most grids show a mixture - a few complete lines, several partial ones, and at least one empty cell.
The arithmetic is worth stating exactly, because different sites do it differently and get different grids. This calculator writes the date as DD/MM/YYYY with the day and month zero-padded to two digits, then takes all eight digits in that string. Every digit greater than zero goes into the cell bearing that number; zeros are discarded, because the grid has no cell for a zero. A birth date of 07/03/1994, for example, contributes 7, 3, 1, 9, 9 and 4 - six digits, with 9 landing twice.
That means an eight-digit date can never fill more than eight of the nine cells, and dates rich in zeros fill fewer. It also means the year does most of the work: two of the four year digits are shared by everyone born in the same century, which is why the day and month are what make one grid differ from another. Nothing here depends on your birth time or place; only the calendar date is used.
For educational purposes. Astrological interpretations are traditional and not a substitute for professional advice.