---
name: "ms_doy2md"
section: "3"
platform: "linux"
package: "libmseed-doc"
version: "2.19.8-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ms_doy2md"
---

# ms\_doy2md(3)

Convert between day of year and month and day of month

## NAME

ms\_doy2md - Convert between day of year and month and day of month

## SYNOPSIS

```
#include <libmseed.h>
int  ms_doy2md ( int year, int jday, int *month, int *mday );
int  ms_md2doy ( int year, int month, int mday, int *jday );
```

## DESCRIPTION

**ms\_doy2md** calculates the *month* and day of month (*mday*) for a given *year* and day of year (*jday*).

**ms\_md2doy** calculates the day of year (*jday*) for a given *year*, *month* and day of month (*mday*).

For both routines the expected and resulting ranges for each value are:

```
year  : 1900 - 2100
jday  : 1 - 366
month : 1 - 12
mday  : 1 - 31
```

A day of year of 366 corresponds to the last day of a leap year.

## RETURN VALUES

**ms\_doy2md** returns 0 on success and -1 on error.

**ms\_md2doy** returns 0 on success and -1 on error.

## AUTHOR

```
Chad Trabant
IRIS Data Management Center
```