( ( On ( ( the ( vernal equinox ) ) ( -LRB- ( ( ( ( the ( first day ) ) ( of spring ) ) ( for ( ( the ( Earth 's ) ) ( northern hemisphere ) ) ) ) -RRB- ) ) ) ) ( both ( hemispheres ( ( have ( ( ( days and ) nights ) ( of ( ( 12 hours ) each ) ) ) ) ; ) ) ) )
(ROOT (S (PP (IN On) (NP (NP (DT the) (JJ vernal) (NNS equinox)) (PRN (-LRB- -LRB-) (NP (NP (DT the) (JJ first) (NN day)) (PP (IN of) (NP (NN spring))) (PP (IN for) (NP (NP (DT the) (NN Earth) (POS 's)) (JJ northern) (NN hemisphere)))) (-RRB- -RRB-)))) (NP (DT both)) (ADVP (RB hemispheres)) (VP (VBP have) (NP (NP (NNS days) (CC and) (NNS nights)) (PP (IN of) (NP (NP (CD 12) (NNS hours)) (NP (DT each)))))) (: ;)))
On the vernal equinox (the first day of spring for the Earth's northern hemisphere) both hemispheres have days and nights of 12 hours each;
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (QP (JJR fewer) (IN than) (CD 24)) (NNS hours)) (PP (IN of) (NP (NP (NN daylight)) (PP (IN in) (NP (NN alaska)))))) (PP (IN during) (NP (NP (DT each) (NN day)) (PP (IN in) (NP (NNP april))))) (SBAR (IN because) (S (NP (NP (NN earth) (POS 's)) (NN rotation)) (VP (VBZ causes) (NP (DT both) (NN day) (CC and) (NN night)))))) (. .)))