HP35S - Date of Easter

[Roberto Volpi]

Easter is approaching, so I take the opportunity to submit my first program for my beloved HP35S.

It is largely inspired by programs of classic HP calculators. Nevertheless, it takes advantage of the visibility of both y and x stacks.

HOW IT WORKS:

Input the year, and it gives its date of Easter in the stack y in month.day format. The input year is displayed in the stack x.

It works starting from 1583, or the year of introduction of the Gregorian Calendar in your country, till 3999.

Those who consider this period of time insufficient for their scope, may easily expand it.

Happy Easter!

Roberto Volpi


001. LBL P
002. STO Y
003. STO A
004. 19
005. XEQ P067
006. 11
007. STO XA
008. /
009. STO B
010. 44
011. STO +A
012. 1
013. RCL Y
014. %
015. IP
016. +
017. 32
018. %
019. 0.2
020. +
021. IP
022. STO +A
023. CLX
024. 75
025. %
026. IP
027. STO C
028. STO -A
029. RCL A
030. 30
031. XEQ P067
032. RCL B
033. X<>Y
034. X≤Y?
035. ISG A
036. RCL A
037. STO D
038. +/-
039. RCL Y
040. 0.8
041. /
042. IP
043. +
044. RCL C
045. –
046. 3
047. +
048. STO A
049. 7
050. XEQ P067
051. +/-
052. RCL D
053. –
054. 26
055. +
056. X>0?
057. XEQ P060
058. 69
059. –
060. 1
061. %
062. 4
063. +
064. RCL Y
065. R/S
066. GTO P001
067. /
068. LASTX
069. X<>Y
070. IP
071. X
072. STO -A
073. RCL A
074. RTN


LN = 249
CK = 10D9