Table 2. Variation of mood and sleepiness relative to time of day and circadian phase.

Refer to Figure 4 for a graphical display of POMS TMD, Confusion, Fatigue, and Vigor results. Refer to Figure 5 for a graphical display of SSS results. POMS: Profile of Mood States; TMD: Total Mood Disturbance; SSS: Stanford Sleepiness Scale. Degrees of freedom for time-of-day analyses: day 1, 382; time of day 7, 382; day × time of day 7, 382; for circadian phase analyses: day 1, 374; circadian phase 11, 374; day × circadian phase 11, 374.

Subscale & Effect:	Time of Day:		Circadian Phase:
	F-value:	P-value	F-value:	P-value:
POMS TMD
Day	39.58	<0.001	38.99	<0.001
Time/Phase	26.07	<0.001	9.85	<0.001
Day × Time/Phase	0.98	0.449	0.79	0.647
POMS Anger
Day	4.04	0.051	3.13	0.079
Time/Phase	5.02	<0.001	2.65	0.004
Day × Time/Phase	1.35	0.251	1.20	0.292
POMS Confusion
Day	13.82	<0.001	14.13	<0.001
Time/Phase	15.89	<0.001	7.09	<0.001
Day × Time/Phase	0.60	0.753	1.27	0.243
POMS Depression
Day	3.53	0.226	3.08	0.086
Time/Phase	4.89	<0.001	2.25	0.014
Day × Time/Phase	1.26	0.275	0.91	0.536
POMS Fatigue
Day	28.48	<0.001	29.68	<0.001
Time/Phase	26.13	<0.001	9.99	<0.001
Day × Time/Phase	0.58	0.773	0.94	0.504
POMS Tension
Day	3.87	0.056	3.02	0.090
Time/Phase	4.31	<0.001	2.02	0.030
Day × Time/Phase	1.29	0.263	1.30	0.227
POMS Vigor
Day	10.11	0.002	10.79	0.001
Time/Phase	6.55	<0.001	4.29	<0.001
Day × Time/Phase	0.59	0.767	0.45	0.930
SSS Sleepiness
Day	1.63	0.202	1.51	0.220
Time/Phase	23.18	<0.001	9.54	<0.001
Day × Time/Phase	0.97	0.452	0.53	0.883