Lilly was born at the village of Diseworth in Leicestershire. His time of birth is not known and confusion exists over the date of birth.
This chart is the one that his contemporary, John Gadbury, published in his Collection of Nativities (1661) as a result of a rectification performed by James Blackwell. The time, given in the old style format (of 14hrs and 8 mins after noon), equates to 2:08 am 1st May 1602.
Gadbury's commentary on the chart reads (p.188):
The person whose geniture this is (to puzzle the understandings of the inquisitous) hath pretended himself to have two several nativities:
(1.) In his Almanac of 1645 he tells his reader (in the Epistle thereunto) that he had the Moon in Pisces, which makes him a piece of a good fellow, &c., which (if true) he must be born the 5th or 6th of May 1602.
(2.) In his Introduction under his effigies, he says he was born on May 1st 1602, and then the Moon will not be in Pisces but in Capricorn, as in this figure. I am of the opinion he hath not the Moon in Pisces but in Capricorn, and therefore believe this to be his right nativity; the rather because my loving friend Mr. James Blackwell hath proved it so to be by thirteen several arguments or accidents printed a year-and-a-half since by itself. In which little tract, the ingenious Artist may meet with a concise method for calculating and judging a nativity; and unto which I refer the desirous reader for further satisfaction in this geniture.
The reason why I am no larger herein is: because I would not be esteemed either envious or partial.
Being born into a rural family, it's possible that Lilly did not know his correct birth details and was himself, working with rectified data. A chart for the 6th of May, when the Moon was in Pisces, is given below: