nuttx/libs/libc/time/lib_dayofweek.c
Alin Jerpelea 3d6185709f libs: Author David Sidrane: update licenses to Apache
David Sidrane has submitted the ICL and we can migrate the licenses
 to Apache.

Gregory Nutt has submitted the SGA and we can migrate the licenses
 to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-03-22 19:28:38 -07:00

92 lines
3.3 KiB
C

/****************************************************************************
* libs/libc/time/lib_dayofweek.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <nuttx/time.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Constant Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_dayoftheweek
*
* Description:
* Get the day of the week
*
* Input Parameters:
* mday - The day of the month 1 - 31
* month - The month of the year 1 - 12
* year - the year including the 1900
*
* Returned Value:
* Zero based day of the week 0-6, 0 = Sunday, 1 = Monday... 6 = Saturday
*
****************************************************************************/
int clock_dayoftheweek(int mday, int month, int year)
{
if (month <= 2)
{
year--;
month += 12;
}
month -= 2;
return (mday + year + year / 4 - year / 100 + year / 400 +
(31 * month) / 12) % 7;
}