A calendar is a system of organizing times for social, religious, commercial or administrative purposes. This is done giving names to intervals, typically days, weeks, months and years. A night out is the designation of a single, specific day within such something. A calendar is also a physical record (often paper) of such a system. A calendar can also signify a list of planned events, like a judge calendar or a partially or completely chronological list of documents, like a calendar of wills.
Times in a january 2018 calendar (such as years and months) are usually, though not necessarily, synchronised with the circuit of the sun or the moon. The most frequent type of pre-modern calendar was the lunisolar calendar, a lunar calendar that once in a while offers one intercalary month to stay synchronised with the solar 12 months over the long term.
The word calendar is extracted from calendae, the word for the first day of the month in the Roman calendar, related to the verb calare "to call out", referring to the "calling" of the new moon when it was initially seen. Latin calendarium supposed "account publication, register" (as accounts were resolved and obligations were gathered on the calends of every month). The Latin term was followed in Old France as calendier and from there in Middle British as calender by the 13th century (the spelling calendar is early on modern).
January 2018 Calendar Source: https://towncalendars.com/january-2018-calendar.html