Standard nezirus is for thirty days.  If he said: “I am a nazir [for] one large [term],” [or] “I am a nazir [for] one small [term],” [or] even “. . . from here until the end of the world” —- [he is] a nazir for thirty days.  [One who says:] “I am a nazir and one day,” [or] “I am a nazir and one hour,” [or] “I am a nazir one [term] and a half” —- he is a nazir for two [terms].  [If he says:] “I am a nazir for thirty days and one hour,” [he is] a nazir for thirty-one days, because one cannot extend nezirus by hours.