Start period sets the clock to this period's starting value and immediately starts it running — so press it when play begins, not during the break. The key shows ▶ in this mode.

Set period only changes which period the board shows and does not touch the clock at all: a running clock keeps running, at the same value. Use it to correct a mislabelled period mid-play, or when something else is driving your clock.

Either way your sport's own rules for entering a period still apply — a basketball board grants that half's timeouts on both.

How many periods your board has depends on its sport: 1–2 for soccer, rugby and handball, 1–3 for ice hockey, 1–4 for American football, flag football and basketball, 1–5 for tennis, and up to the scheduled round count for boxing. A period your board doesn't have shows ⚠️ on the key.

Half time, full time and overtime have no number and aren't available here — set those from the control page.