Siddur Sim Shalom for weekdays is a traditional prayer book that is widely used in the Jewish community during weekdays. Apart from Siddur Sim Shalom, there are several synonyms that can be used to refer to this prayer book. Some of them include Siddur Tefillah, Siddur Lev Shalem, Siddur Eit Ratzon, and Siddur Birkat Shalom. While the contents of each of these prayer books may differ slightly, they all contain the same basic prayers and are used for the same purpose. Hence, the choice of which prayer book to use is usually a matter of personal preference and tradition. Whatever the case may be, Siddur Sim Shalom remains a popular choice for weekday prayers.