The Roman calendar changed its form several times between the founding of Rome and the fall of the Roman Empire. The common calendar widely used today is known as the Gregorian calendar and is a refinement of the Julian calendar where the length of the year has been adjusted from 365.25 days to 365.2425 days (a 0.002% change).
From at least the period of Augustus on, calendars were often inscribed in stone and displayed publicly. Such calendars are called fasti.
The original Roman calendar is believed to have been a lunar calendar, which may have been based on one of the Greek lunar calendars. As the time between new moons averages 29.5 days its months were constructed to be either hollow (29 days) or full (30 days).
Roman writers attributed the original Roman calendar to Romulus, the mythical founder of Rome, though there is no other evidence for the existence of such a calendar and Romulus was often cited as the founder of practices whose origins were unknown to later Romans. According to these writers, Romulus' calendar had ten months with the spring equinox in the first month (likely based on the names of the last months of the year):
Roses R Red
Just to know that I will see you today
Makes me wake up early just to see your face
Makes that bus ride to school seem A-okay
Girl, i've never felt this way
I've never been in love to know just how it feels
And everytime I see you girl my heart beats are real
So if roses are real and violets are blue
Gilr what i'm trying to say
I think that i'm in love with you
Roses are red
Violets are blue girl
I'm not sure but I think i'm in love with you
With you that's right that's right
I'm not really sure but I think i'm in love with you
It's kind of strange to me
Now I know what to say
But till see your face
And then my mind just goes blank
the butterflies then come
And then my knees get weak
Girl I can hardly speak
As crazy as it seems
I don't want school to end
So that I can stare at you and try to pretend
So if roses are red and violets are blue
Girl what I am tryin to say
I think that i'm in love with you
Roses are red
Violets are blue girl
I'm not sure but I think i'm in love with you
With you that's right that's right
I'm not really sure but I think i'm in love with you
And everytime I see you girl my heartbeats are real
So if roses are red and violets are blue
Girl what I am trying to say
I think that i'm in love with you
Roses are red
Violets are blue girl
I'm not sure but I think i'm in love with you
With you that's right that's right
I'm not really sure but I think i'm in love with you