1. Binary date storage
These routines allow you to save dates using only
3-bytes.
bytes = date2bytes{{12, 31, 1997})
--bytes = {byte 1, byte 2, byte 3}
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--date format is {month, day, year}
--supports years 0-45099
--I could be EASILY presuaded to allow for
--negative years. (B.C. years)
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global function date2bytes(sequence dte)
integer temp
sequence bytes
dte[1..2] = dte[1..2] - 1
bytes = repeat(0, 3)
dte[3] = dte[3] * 372
dte[2] = dte[2] * 12
temp = dte[1] + dte[2] + dte[3]
bytes[1] = remainder(temp, 256)
temp = temp - bytes[1]
temp = temp / 256
bytes[2] = remainder(temp, 256)
temp = temp - bytes[2]
temp = temp / 256
bytes[3] = temp
return bytes
end function
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global function bytes2date(sequence bytes)
integer temp
sequence dte
temp = bytes[3] * 65536
temp = temp + bytes[2] * 256
temp = temp + bytes[1]
dte = repeat(0, 3)
--Month
dte[1] = remainder(temp, 12)
temp = temp - dte[1]
temp = temp / 12
--Day
dte[2] = remainder(temp, 31)
temp = temp - dte[2]
temp = temp / 31
--Year
dte[3] = temp
dte[1..2] = dte[1..2] + 1
return dte
end function
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sequence dte, bytes, dte2
dte = {6, 25, 1997}
bytes = date2bytes(dte)
dte2 = bytes2date(bytes)
? dte
? dte2
? bytes
