Table 1.

Sleep Times and Circadian Phase

	Young	Older
Sleep Onset	23.89 ± 0.87	22.88 ± 1.02*
Sleep Offset	6.95 ± 0.63	6.44 ± 1.27
Baseline Tmin	5.09 ± 1.80	4.65 ± 1.62
Baseline DLMO 50%	22.74 ± 1.42	22.19 ± 1.33
Baseline Melatonin Midpoint	2.32 ± 1.36	2.04 ± 1.18
Post-tx Melatonin Midpoint	3.57 ± 1.41	3.12 ± 1.29

Times are in decimal clock time ± SD

^*p = 0.011