1 files changed, 56 insertions, 0 deletions
diff --git a/time/isLeap.c b/time/isLeap.c
new file mode 100644
index 0000000..3c846aa
--- /dev/null
+++ b/time/isLeap.c
@@ -0,0 +1,56 @@
+/*
+ * (C)2012 Michael Duane Rice All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer. Redistributions in binary
+ * form must reproduce the above copyright notice, this list of conditions
+ * and the following disclaimer in the documentation and/or other materials
+ * provided with the distribution. Neither the name of the copyright holders
+ * nor the names of contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* $Id: isLeap.c 2325 2013-04-02 21:22:16Z swfltek $ */
+
+/*
+    Return 1 if 'year' is a leap year, else 0.
+*/
+
+#include <stdlib.h>
+
+unsigned char
+is_leap_year(int year)
+{
+    div_t           d;
+
+    /* year must be divisible by 4 to be a leap year */
+    if (year & 3)
+        return 0;
+
+    /* If theres a remainder after division by 100, year is not divisible by 100 or 400 */
+    d = div(year, 100);
+    if (d.rem)
+        return 1;
+
+    /* If the quotient is divisible by 4, then year is divisible by 400 */
+    if ((d.quot & 3) == 0)
+        return 1;
+
+    return 0;
+}