Rosh Chodesh
40. In some places, people do not cut hair or nails on Rosh Chodesh (צוואת ר' יהודה החסיד סי' מ''ח, מ''ב סי' ר''ס סק''ז ). L’chatchila one should be careful about this.
41. Rosh Chodesh on erev Shabbos. Some poskim write that one should not get a haircut on Rosh Chodesh even when it falls on erev Shabbos (מג''א סי' ר''ס ). The poskim discuss whether one should also be careful about Tzavaas R’ Yehuda HaChassid and not cut his nails or whether there is room to be meikel.
42. Some hold that one who cuts his nails every erev Shabbos may cut his nails even when erev Shabbos is Rosh Chodesh. This is unlike haircuts, as it is not common to get a haircut every week (משמעות המג''א הנ''ל, שבעים תמרים סי' נ''ו, שו''ת אלף המגן סי' י''ב, שו''ת מהר''ם מבריסק ח''ב סי' צ''ט, שו''ת משיב הלכה ח''ב סי' ד', שו''ת רבבות אפרים ח''ד סי' צ''ז ).
43. However, others hold one should not cut his nails on Rosh Chodesh even when it is erev Shabbos (מ''ב שם, קיצור שו''ע סי' ע''ב סי''ד ) unless they are long and extend past the flesh, in which case they are meikel and allow cutting them even on Rosh Chodesh that falls on erev Shabbos (כף החיים אות י''ב ).
44. Women. Some say that there is no problem for women to get haircuts or cut their nails on Rosh Chodesh even not for a mitzva purpose (יד אפרים סי' נ''ו ); when necessary, one may rely on this.
45. 1st day of Rosh Chodesh. Some are meikel to allow cutting fingernails on the first day of Rosh Chodesh, as the problem is only on the second day of Rosh Chodesh or on a one-day Rosh Chodesh (יד אפרים בקו''א לצוואת ריה''ח אות נ''ז בשם הדרכי תשובה ).
46. Rosh Chodesh night. Some allow cutting the nails on Rosh Chodesh night, as the problem is only on Rosh Chodesh day (אשל אברהם מהדו''ת סי' תי''ז ); also on the second night of Rosh Chodesh (מילי דחסידותא סי' נ''ז ).
