Once every month, we say a blessing to Hashem for the moon. Our Sages tell us that when we state this blessing, we are greeting the Shechina. Therefore, the best time of the week to recite this is Motzi Shabbos, because we are still dressed in our Shabbos clothes. If it is not recited on Motzi Shabbos, we should still make sure to be properly dressed to greet the Shechina when reciting Kiddush Levana.