Context: The North American mnemonic "spring forward, fall back" (also "spring ahead ...", "spring up ...", and "... fall behind") helps people remember which direction to shift clocks.

Question: What phrase is often used in North America when speaking about DST?
Answer: spring forward, fall back

Question: What is a language like "spring forward, fall back" that acts as a trigger for memory called?
Answer: mnemonic

Question: What does "spring forward, fall back" help people remember?
Answer: which direction to shift clocks