Concept in Definition ABC

One day is the time it takes for the earth from when the sun is at the highest point on the horizon until It is again on it and it was also the first way that man had in ancient times to measure the weather.

Also, as with the year, two different references can be taken to measure the day: the sun on one side and the stars on the other. The first is the most common for all of us who inhabit planet earth since it is the most used in our daily lives and implies the time that the sun takes to arrive twice consecutive to meridian observer. His duration it is 24 hours or if you prefer to handle seconds, 86,400 seconds.

And in the case of using the stars as a reference, also called sidereal day, the time will be measured from the lapse that implies two successive culminations of stars in the local meridian that corresponds. Its duration is a little less than that of the mean solar day, approximately 23 hours, 56 minutes and 4 seconds.

The term day is also used to distinguish it from night, the day being the time from sunrise to sunset.

According to calendar Gregorian that Pope Gregory XIII imposed at the time in the sixteenth century, each day that composes the week has a different name, so we have Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.

Meanwhile and leaving aside this of the equinoxes, the meridians, the minutes and seconds, also the The word day is used to designate some type of holiday, historical event, anniversary, among others, that will aim to remember every year, that same day, a situation that marked a milestone in some area in particular.

So for example we find the International day to fight AIDS, which is set at December 1, so, always for that date, different actions will be prepared to make aware about how to prevent disease.

Also, another of the internationally known days is the of employee, which is celebrated on May 1 of every year since 1889 and which took that particular date for having was the day on which some unionists from the American city of Chicago were executed take part in the days that demanded a working daylabor that does not exceed 8 hours a day.