How much time is needed before or after shabbos to say it is "שכר שבת בהבלעה" (shabbos earnings included with weekday earnings).
Various halachas pertaining to our fourth category "kevashim/shlokos" (preserved and cooked foods).
Understanding the Concept of Something That Was Attached to the Ground or a Tree Going into Shabbos and Then Became Detached on Shabbos (Muktzeh);