Historical Rules · 29 September 2017
Rule 307.5
Official source text from the 29 September 2017 Rules release
If a spell, ability, or effect states that a player can do something only “any time he or she could cast a sorcery,” it means only that the player must have priority, it must be during the main phase of his or her turn, and the stack must be empty. The player doesn’t need to have a sorcery he or she could actually cast. Effects that would preclude that player from casting a spell or casting a sorcery don’t affect the player’s capability to perform that action (unless the action is actually casting a spell or casting a sorcery).