switch to avr-libc 1.8.1 time library

1 files changed, 57 insertions, 0 deletions

diff --git a/time/solar_noon.c b/time/solar_noon.c
new file mode 100644
index 0000000..65bafcc
--- /dev/null
+++ b/time/solar_noon.c
@@ -0,0 +1,57 @@
+/*
+ * (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: solar_noon.c 2365 2013-04-27 15:32:59Z swfltek $ */
+
+/*
+    Return the time of solar noon at the observers position
+*/
+
+#include <time.h>
+
+extern long     __longitude;
+
+time_t
+solar_noon(const time_t * timer)
+{
+    time_t          t;
+    long            n;
+
+    /* determine time of solar noon at the prime meridian */
+    t = *timer % ONE_DAY;
+    t = *timer - t;
+    t += 43200L;
+    t -= equation_of_time(timer);
+
+    /* rotate to observers longitude */
+    n = __longitude / 15L;
+    t -= n;
+
+    return t;
+
+}