indoor room temperature works in about 4-6 weeks for many citrus seeds ive tried.
Millet and others introduced the "baggie method" on this forum- moisten your seed starting medium, place in ziplock with seeds, and place on slightly warm place- old style computer monitor, refrigerator, cable box, and theyll sprout sooner.
I put my baggies in the diffuse sunlight around my citrus in pots in front of a window, and they took 3-6 weeks.
Ive seen key lime seedlings up after about 2 weeks outdoors in summer.
warmer = faster.