Annotation of embedaddon/php/ext/date/lib/astro.h, revision 1.1.1.1
1.1 misho 1: /* This macro computes the length of the day, from sunrise to sunset. */
2: /* Sunrise/set is considered to occur when the Sun's upper limb is */
3: /* 35 arc minutes below the horizon (this accounts for the refraction */
4: /* of the Earth's atmosphere). */
5: #define day_length(year,month,day,lon,lat) \
6: __daylen__( year, month, day, lon, lat, -35.0/60.0, 1 )
7:
8: /* This macro computes the length of the day, including civil twilight. */
9: /* Civil twilight starts/ends when the Sun's center is 6 degrees below */
10: /* the horizon. */
11: #define day_civil_twilight_length(year,month,day,lon,lat) \
12: __daylen__( year, month, day, lon, lat, -6.0, 0 )
13:
14: /* This macro computes the length of the day, incl. nautical twilight. */
15: /* Nautical twilight starts/ends when the Sun's center is 12 degrees */
16: /* below the horizon. */
17: #define day_nautical_twilight_length(year,month,day,lon,lat) \
18: __daylen__( year, month, day, lon, lat, -12.0, 0 )
19:
20: /* This macro computes the length of the day, incl. astronomical twilight. */
21: /* Astronomical twilight starts/ends when the Sun's center is 18 degrees */
22: /* below the horizon. */
23: #define day_astronomical_twilight_length(year,month,day,lon,lat) \
24: __daylen__( year, month, day, lon, lat, -18.0, 0 )
25:
26:
27: /* This macro computes times for sunrise/sunset. */
28: /* Sunrise/set is considered to occur when the Sun's upper limb is */
29: /* 35 arc minutes below the horizon (this accounts for the refraction */
30: /* of the Earth's atmosphere). */
31: #define timelib_astro_sun_rise_set(ts,lon,lat,hrise,hset,rise,set) \
32: timelib_astro_rise_set_altitude( ts, lon, lat, -35.0/60.0, 1, hrise, hset, rise, set )
33:
34: /* This macro computes the start and end times of civil twilight. */
35: /* Civil twilight starts/ends when the Sun's center is 6 degrees below */
36: /* the horizon. */
37: #define civil_twilight(ts,lon,lat,start,end) \
38: timelib_astro_rise_set_altitude( ts, lon, lat, -6.0, 0, start, end )
39:
40: /* This macro computes the start and end times of nautical twilight. */
41: /* Nautical twilight starts/ends when the Sun's center is 12 degrees */
42: /* below the horizon. */
43: #define nautical_twilight(ts,lon,lat,start,end) \
44: timelib_astro_rise_set_altitude( ts, lon, lat, -12.0, 0, start, end )
45:
46: /* This macro computes the start and end times of astronomical twilight. */
47: /* Astronomical twilight starts/ends when the Sun's center is 18 degrees */
48: /* below the horizon. */
49: #define astronomical_twilight(ts,lon,lat,start,end) \
50: timelib_astro_rise_set_altitude( ts, lon, lat, -18.0, 0, start, end )
51:
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