Mathcad day number in the year and solar declination angle
- 1. Day number in the year and Solar Declination Angle.xmcd This procedure calculates the number of days in a given date and it applies it to the computation of the solar declination angle, 隆, ORIGIN 1 days 31 28 31 30 31 30 31 31 30 31 30 31 ( ) T N N1 0 Ni daysi 1 Ni 1 i 2 12 for N return 削 N T 0 31 59 90 120 151 181 212 243 273 304 334 ( ) n is the day number in the year for a given date: D Month day ( ) NMonth day 削 Example: Calculate the day number in the year for June 1 Month 6 削 day 1 削 n D Month day ( ) 152 削 An application of this day number in the year is in the calculation of The solar declination angle, 隆, 隆 n ( ) 23.45属 sin 360属 284 n ( ) 365 削 隆 n ( ) 22.0属 The solar declination has a maximum value of +23.45o on June 21 and a minimum value of 23.45o on December 21. Month 6 削 day 21 削 n D Month day ( ) 172 削 隆max 隆 n ( ) 23.45属 削 QED Month 12 削 day 21 削 n D Month day ( ) 355 削 隆max 隆 n ( ) 23.45 属 削 QED Q.E.D. or QED is an initialism of the Latin phrase "quod erat demonstrandum", literally meaning "what was to be shown" Julio C. Banks page 1 of 1