The star sign calculator returns the western zodiac sign for a date of birth: the sun sign of newspaper and magazine astrology, drawn from twelve segments of the year running roughly from the 21st of one month to the 20th of the next. Enter a date and it names the sign, its element and its dates.
The boundaries between signs are the reason people get different answers from different sources. The true cusp is an astronomical moment — the point at which the sun crosses from one thirty-degree segment of the ecliptic to the next — and that moment lands at a different time of day each year, and at a different time again depending on the time zone applied to it. A birth late on 22 August can therefore be read as Leo in one table and Virgo in another. Where a date sits within a day of a boundary, this calculator says so rather than pretending to a precision the method does not have.
It is also worth separating this from the sidereal zodiac used in Indian astrology, which is offset by roughly 23 degrees because it is tied to the fixed stars rather than to the equinox, and which will give most people a different sign entirely. Nothing here is a statement about anybody's character — it is a lookup from a date to a name.