==A Delayed Milah==
# A delayed Milah may not take place on Shabbat or Yom Tov.<ref>Kitzur S"A 163:4</ref>
# According to Ashkenazim, one may perform a delayed [[Brit Milah]] on Thursday or Friday even if it will cause a situation of Pikuach Nefesh, however, Sephardim hold that one should not perform a delayed [[Brit Milah]] on Thursday or Friday. <Ref>
* The Gemara [[Shabbat]] 19a quotes the Briatta which states that one may not board a boat in order to travel on [[Shabbat]] unless one got on before 3 days before [[Shabbat]] (whether or not this includes Wednesday, see Mishna Brurah 248:4).