# take a unix date and transform it into a julian day (ie (1998, 13) = 13th day of 1998)
sub unixtoj
{
- my $t = shift;
- my ($year, $day) = (gmtime($t))[5,7];
-
- if ($year < 100) {
- $year += ($year < 50) ? 2000 : 1900;
- }
- return ($year, $day+1);
+ my $t = shift;
+ my ($year, $day) = (gmtime($t))[5,7];
+
+ if ($year < 100) {
+ $year += ($year < 50) ? 2000 : 1900;
+ }
+ return ($year, $day+1);
}
# take a unix and return a julian month from it
{
my $t = shift;
my ($mon, $year) = (gmtime($t))[4..5];
- return ($year, $mon);
+ if ($year < 100) {
+ $year += ($year < 50) ? 2000 : 1900;
+ }
+ return ($year, $mon + 1);
}
# take a julian date and subtract a number of days from it, returning the julian date
sub sub
{
- my ($year, $day, $amount) = @_;
- my $diny = isleap($year) ? 366 : 365;
- $day -= $amount;
- while ($day <= 0) {
- $day += $diny;
- $year -= 1;
- $diny = isleap($year) ? 366 : 365;
- }
- return ($year, $day);
+ my ($year, $day, $amount) = @_;
+ my $diny = isleap($year) ? 366 : 365;
+ $day -= $amount;
+ while ($day <= 0) {
+ $day += $diny;
+ $year -= 1;
+ $diny = isleap($year) ? 366 : 365;
+ }
+ return ($year, $day);
}
sub add
{
- my ($year, $day, $amount) = @_;
- my $diny = isleap($year) ? 366 : 365;
- $day += $amount;
- while ($day > $diny) {
- $day -= $diny;
- $year += 1;
- $diny = isleap($year) ? 366 : 365;
- }
- return ($year, $day);
+ my ($year, $day, $amount) = @_;
+ my $diny = isleap($year) ? 366 : 365;
+ $day += $amount;
+ while ($day > $diny) {
+ $day -= $diny;
+ $year += 1;
+ $diny = isleap($year) ? 366 : 365;
+ }
+ return ($year, $day);
}
# take a julian month and subtract a number of months from it, returning the julian month
sub subm
{
- my ($year, $mon, $amount) = @_;
- $mon -= $amount;
- while ($mon <= 0) {
- $mon += 12;
- $year -= 1;
- }
- return ($year, $mon);
+ my ($year, $mon, $amount) = @_;
+ $mon -= $amount;
+ while ($mon <= 0) {
+ $mon += 12;
+ $year -= 1;
+ }
+ return ($year, $mon);
}
sub addm
{
- my ($year, $mon, $amount) = @_;
- $mon += $amount;
- while ($mon > 12) {
- $mon -= 12;
- $year += 1;
- }
- return ($year, $mon);
+ my ($year, $mon, $amount) = @_;
+ $mon += $amount;
+ while ($mon > 12) {
+ $mon -= 12;
+ $year += 1;
+ }
+ return ($year, $mon);
}
sub cmp
{
- my ($y1, $d1, $y2, $d2) = @_;
- return $d1 - $d2 if ($y1 == $y2);
- return $y1 - $y2;
+ my ($y1, $d1, $y2, $d2) = @_;
+ return $d1 - $d2 if ($y1 == $y2);
+ return $y1 - $y2;
}
# is it a leap year?
sub isleap
{
- my $year = shift;
- return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0;
+ my $year = shift;
+ return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0;
}