(PHP 4, PHP 5, PHP 7)

jddayofweekReturns the day of the week


mixed jddayofweek ( int $julianday [, int $mode = CAL_DOW_DAYNO ] )

Returns the day of the week. Can return a string or an integer depending on the mode.



A julian day number as integer

Calendar week modes
Mode Meaning
0 (Default) Return the day number as an int (0=Sunday, 1=Monday, etc)
1 Returns string containing the day of week (English-Gregorian)
2 Return a string containing the abbreviated day of week (English-Gregorian)

Return Values

The gregorian weekday as either an integer or string.

add a note add a note

User Contributed Notes 1 note

kevind at communitycolor dot com
1 year ago
You need to check to see how your client wants to represent the day of week. This function returns 0 for Sundays. ISO 8601 uses 7 for Sundays.

BTW, You can also calculate the day of week with modular division:

$dow = (1 + $julianday) % 7; // returns 0 for Sundays.
$dow = ($julianday % 7) + 1; // returns 7 for Sundays.


To make matters confusing. The Julian Date starts at noon UTC. Some programs such as SQLITE3 use real numbers to record date and time. If you pass this function a float; it will return a different day of week for the morning than for the afternoon.

When given a julianday with a decimal part you will need to add a half day and may need further adjustment for your timezone.
To Top