The Mishna (Nazir 1:3) in today’s daf (Nazir 7b) informs us that if someone made a vow to become a Nazir for thirty days and one hour, they are required to observe the laws of Nezirut for thirty-one days because אֵין נְזִירוּת לְשָׁעוֹת – the measure of time-bound commitment by a Nazir is according to days, not hours.
Clearly, what this Mishna wishes to teach us is that the choice to be a Nazir is not a casual choice but, instead, a meaningful one. And just as a hotel is booked per day rather than per hour, so too, Nezirut is committed to per day rather than per hour.
However, I believe that there is a further reason why Nezirut is not committed to ‘by the hour’ – because in such a case the Nazir would be counting down the hours until the Nazir period ends; rather than being immersed in the Nazir experience for X amount of time, they will be looking at their watch, moment by moment, until X amount of time ends.
Of course, it may be true that most Nezirim commit to being a Nazir for a fixed amount of time – which means that most Nezirim are palpably conscious of the nearing of the end of their Nezirut period. Still, there is a big difference between day-consciousness and hour-consciousness, and if you are constantly checking the hour, what this means is that you are not fully engaged in the moment.
Ultimately, by adopting the view of אֵין נְזִירוּת לְשָׁעוֹת, I believe our Sages are teaching us that whatever the view of the choice to be a Nazir, if someone is going to be a Nazir then they should be one. And in terms of us, if we are going to do something then we should do it – without constantly checking the time to find out when the task or role we are doing is about to end.