Revolving Time

As long as it's your turn, basic lands you control have: {t}; at the beginning of your next upkeep, add one mana of any color this land would not produce to your mana pool.
As long as it's not your turn, nonland, noncreature permanents you control have: {t}; add {c} to your mana pool. This mana does not empty from your mana pool until your next upkeep.