Variable

Category

Sleeping Time

Total

After 1:00 am (late)

Before 1:00 am (early)

Sleeping hours

<6 hours

138

63

201

>6 hours

32

33

65

Total

170

96

266

Awake time

Before 7:00 am

55

65

120

After 7:00 am

103

27

130

Total

158

92

250

Late sleep associated with bad temper (next day)

Yes

82

36

118

No

88

60

148

Total

170

96

266

Late sleep affects academic achievement

Strongly

70

64

134

Average

95

31

126

Weakly

5

1

6

Late sleep affects work success

Strongly

93

63

156

Average

75

33

108

Weakly

2

0

2

Late sleep decreases work satisfaction

Yes

142

85

227

No

28

11

39

Early sleep brings

Happiness

159

90

249

Depression

11

6

17