Sirea said:Legend Lore from the PHB can have a casting time up to 1d10 days and even 2d6 weeks.
A strict interpretation of the rules makes this impossible to cast.
The text of the Legend Lore spell states that 'during the casting, you cannot engage in other than routine activities: eating, sleeping, and so forth'. So there's a specific exception to the general rule listed there ... No such exception is listed for Awaken or Hallow.