Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos) By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
First Section – the Positive Commandments
28. It is a positive commandment to rest from work on Shavuos
As it says in Vayikra (Leviticus) 23:21,”And you shall call it on this very day, a day of holiness.”
This applies in all places and at all times, for men and for women.