Is there a difference of 2 minutes?
Answer: ① Sometimes there is no difference. For example: 04: 00: Yin Shi, two minutes short, 03: 58, or Yin Shi, 04: 02, still.
It's Yin Shi.
(2) Sometimes there are differences. For example: 05: 00 (Shi Mao), two minutes to 04: 58 (Yin Shi). This is the difference.