Can you play a land during an extra turn granted by Time Walk effects?

Playing a land is governed by CR 305.2, which states that a player may play a land on their turn during their main phase when the stack is empty, subject to a limit of one land per turn (unless an effect increases that limit). An extra turn granted by effects like Time Walk or Time Warp is a completely normal turn in all respects — it has all the same phases and steps, and the land-play limit resets for that turn.

CR 500.1 confirms that each turn follows the same structure: beginning phase, precombat main phase, combat phase, postcombat main phase, and ending phase. There is no rule that strips extra turns of the ability to play lands; extra turns are simply additional turns inserted into the turn order (CR 500.7).

The land-play limit (default: one) is tracked per turn. When your extra turn begins, your land-play count resets to zero, so you have a fresh opportunity to play a land. If you had already played a land during your normal turn before the extra turn started, that does not carry over — each turn's count is independent.

Concrete example: You play a land on your regular turn, then cast Time Warp, giving yourself an extra turn. When that extra turn's precombat main phase begins with the stack empty, you may play one land from your hand as normal, because the land-play count for that new turn starts fresh at zero.

Note: If an effect says "you can't play lands this turn," that restriction applies only to the specific turn it was created in, not to any extra turns granted later, unless the effect's text explicitly says otherwise.