HP 15C: Approximate Length of Sunlight During a Day
For the HP
35S version, please click here:
Source: Total
Daily Amount of Solar Radiation - HP 67/97 Energy Conservation Pac, December
1978, Author: Hewlett Packard
Instructions:
Y
Stack: Enter the latitude (North as
positive, South as negative). Use the
D.MMSS (degrees-minutes-seconds) format
X
Stack: The number of days after March
21. A 365 day year is assumed, as well
as assuming March 21 is the vernal equinox.
Run the
program.
This is an
approximation.
Program:
|
Step
|
Key
|
Key Code
|
|
001
|
LBL E
|
42, 21, 5
|
|
002
|
DEG
|
43, 7
|
|
003
|
.
|
48
|
|
004
|
9
|
9
|
|
005
|
8
|
8
|
|
006
|
5
|
5
|
|
007
|
6
|
6
|
|
008
|
*
|
20
|
|
009
|
SIN
|
23
|
|
010
|
2
|
2
|
|
011
|
3
|
3
|
|
012
|
.
|
48
|
|
013
|
4
|
4
|
|
014
|
5
|
5
|
|
015
|
*
|
20
|
|
016
|
X<>Y
|
34
|
|
017
|
>H
|
43, 2
|
|
018
|
TAN
|
25
|
|
019
|
X<>Y
|
34
|
|
020
|
TAN
|
25
|
|
021
|
CHS
|
16
|
|
022
|
*
|
20
|
|
023
|
COS^-1 (ACOS)
|
43, 32
|
|
024
|
>RAD
|
42, 3
|
|
025
|
2
|
2
|
|
026
|
4
|
4
|
|
027
|
*
|
20
|
|
028
|
π
|
43, 26
|
|
029
|
÷
|
10
|
|
030
|
>H.MS
|
42, 2
|
|
031
|
RTN
|
43, 32
|
Example:
Los Angeles,
April 17. Latitude of 34°03’ N, 27 days
after March 21.
Result: approximately 12.5735 (12 hours, 57 minutes,
35 seconds)
Sydney, June
21. Latitude of 33°51’31” S (enter as
-33.5131), 92 days after March 21.
Result: approximately 9.4439 (9 hours, 44 minutes, 39
seconds)
Rome,
September 1. Latitude of 41°51’ N, 164
days after March 21.
Result: approximately 12.5323 (12 hours, 53 minutes,
23 seconds)
This blog is
property of Edward Shore. 2016
