While many Slavic languages officially use Latin-derived names for the months of the year in the Gregorian calendar, there is also a set of older names for the twelve months that differs from the Latin month names, as they are of Slavic origin. In some languages, such as the Serbian language these traditional names have since been archaized and are thus seldom used.
The original names of the months of the year in the Slavic languages closely follow natural occurrences such as weather patterns and conditions common for that period, as well as agricultural activities.
Many months have several alternative names in different regions; conversely, a single "Slavic name" may correspond to different "Roman names" (for different months, usually following each other) in different languages.