In numerology, it means the three of you are likely to have mid-lives of similar resonance. For the birth day number 28, it is a resonance of emotional and intellectual independence, exploration, and leadership.

The birth day in numerology reveals an aspect of a person's life somewhere in the range of about 32 to about 59 years of age. The beginning of the mid-life cycle is affected by the full birth date. There are three life cycles. The mid-life cycle is 27 years long.

To find the life cycle number, the birth day number is reduced to a digit. 28 reduces to the digit 1, thus: 2+8=10, 1+0=1

Those born on the 1st, 10th, or 28th day of the month all have the same birth day number 1.

Two or more in a family having the same birth day number is not uncommon, especially in larger families. It underscores the general tendency for family members to live somewhat similar lifestyles.

As additional information, the birth month number reduced to a digit is related to the first life cycle in the same way the birth day is related to the second life cycle. The birth year reduced to a digit is related to the third and last life cycle.

The length of the first life cycle is affected by the full birth date and can range from 27 to 36 years. The second life cycle is 27 years in length. The third life cycle lasts until transition to non-physical existence.