( ( The ( Julian calendar ) ) ( ( had ( ( ( ( a ( 12-month year ) ) ( measuring ( 365.25 days ) ) ) - ) ( an ( attempt ( to ( duplicate ( ( the time ) ( it ( takes ( the ( Earth ( to ( ( make ( a ( complete revolution ) ) ) ( around ( the sun ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Julian) (NN calendar)) (VP (VBD had) (NP (NP (NP (DT a) (JJ 12-month) (NN year)) (VP (VBG measuring) (NP (CD 365.25) (NNS days)))) (: -) (NP (DT an) (NN attempt) (S (VP (TO to) (VP (VB duplicate) (NP (NP (DT the) (NN time)) (SBAR (S (NP (PRP it)) (VP (VBZ takes) (NP (DT the) (NN Earth) (S (VP (TO to) (VP (VB make) (NP (DT a) (JJ complete) (NN revolution)) (PP (IN around) (NP (DT the) (NN sun))))))))))))))))) (. .)))
The Julian calendar had a 12-month year measuring 365.25 days - an attempt to duplicate the time it takes the Earth to make a complete revolution around the sun.
(ROOT (S (NP (NNP Earth)) (VP (VBZ makes) (NP (DT a) (JJ complete) (NN revolution)) (NP (ADVP (IN around) (NP (DT the) (NN sun)) (PP (IN about) (ADVP (RB once)))) (DT every) (NN year))) (. .)))