Civil Twilight Duration (sunset to solar depression 6°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Northern Hemisphere (March 1, 2007 to March 31, 2008)
20
25
30
35
Civil Twilight Duration (mean solar minutes after sunset)
40
45
50
55
60
65
70
23.5° N
75
80
30° N
40° N
45° N
85
90
50° N
55° N
58° N
95
100
59° N
60° N
61° N
105
110
Northward Equinox
North Solstice
Southward Equinox
115
South Solstice
120
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/
Civil Twilight Duration (sunset to solar depression 6°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Southern Hemisphere (March 1, 2007 to March 31, 2008)
20
25
30
35
Civil Twilight Duration (mean solar minutes after sunset)
40
45
50
55
60
65
70
23.5° S
75
80
30° S
40° S
45° S
85
90
50° S
55° S
58° S
95
100
59° S
60° S
61° S
105
Northward Equinox
110
North Solstice
Southward Equinox
115
South Solstice
120
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/
Nautical Twilight Duration (sunset to solar depression 12°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Northern Hemisphere (March 1, 2007 to March 31, 2008)
45
50
55
60
65
Nautical Twilight Duration (mean solar minutes after sunset)
70
75
80
85
90
95
100
105
110
115
120
125
23.5° N
30° N
35° N
38° N
130
40° N
135
42° N
140
45° N
145
49° N
150
52° N
155
160
54° N
Northward Equinox
North Solstice
165
170
Southward Equinox
South Solstice
175
180
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/
Nautical Twilight Duration (sunset to solar depression 12°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Southern Hemisphere (March 1, 2007 to March 31, 2008)
45
50
55
60
65
Nautical Twilight Duration (mean solar minutes after sunset)
70
75
80
85
90
95
100
105
110
115
120
125
23.5° S
30° S
35° S
38° S
130
40° S
135
42° S
140
45° S
145
49° S
150
52° S
155
160
54° S
Northward Equinox
North Solstice
165
170
Southward Equinox
South Solstice
175
180
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/
Astronomical Twilight Duration (sunset to solar depression 18°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Northern Hemisphere (March 1, 2007 to March 31, 2008)
70
75
80
85
Astronomical Twilight Duration (mean solar minutes after sunset)
90
95
100
105
110
115
120
125
130
23.5° N
30° N
35° N
135
38° N
140
40° N
42° N
145
150
155
44° N
46° N
47° N
49° N
160
165
Northward Equinox
North Solstice
Southward Equinox
170
South Solstice
175
180
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/
Astronomical Twilight Duration (sunset to solar depression 18°)
Mar 27
Mar 13
Feb 28
Feb 14
Jan 31
Jan 17
Jan 3
Dec 20
Dec 6
Nov 22
Nov 8
Oct 25
Oct 11
Sep 27
Sep 13
Aug 30
Aug 16
Aug 2
Jul 19
Jul 5
Jun 21
Jun 7
May 24
May 10
Apr 26
Apr 12
Mar 29
Mar 15
Mar 1
at the Prime Meridian, Sea Level, Southern Hemisphere (March 1, 2007 to March 31, 2008)
70
75
80
85
Astronomical Twilight Duration (mean solar minutes after sunset)
90
95
100
105
110
115
120
125
130
23.5° S
30° S
35° S
135
38° S
140
40° S
42° S
145
150
155
44° S
46° S
47° S
49° S
160
Northward Equinox
165
North Solstice
Southward Equinox
170
South Solstice
175
180
Analysis by Dr. Irv Bromberg, University of Toronto, Canada
http://www.sym454.org/twilight/