Table 2. Number of non-wear periods and valid wear time per day defined by three different criteria in European school children (n = 1057).

	≥20 min zero counts	≥30 min zero counts	≥60 min zero counts
Median # non-wear periods per valid day (range)	3.1 (1–10)	2.7 (1–7)	2.1 (1–4)
Valid wear time (hrs/day)	13.2	13.4	13.6