# What Number Day of the Year Is It?

## How to Calculate the Day of the Year

### Excel

1. Open Microsoft Excel.
2. Enter the date for which you want to calculate the day of the year in a cell.
3. In a different cell, enter the following formula: =DATE(YEAR(A1), MONTH(A1), DAY(A1))-DATE(YEAR(A1), 1, 1)+1, where A1 is the cell containing the date.
4. Press Enter to calculate the result. The result will be the day of the year for the date entered in cell A1.

2. Enter the date for which you want to calculate the day of the year in a cell.
3. In a different cell, enter the following formula: =DATE(YEAR(A1), MONTH(A1), DAY(A1))-DATE(YEAR(A1), 1, 1)+1, where A1 is the cell containing the date.
4. Press Enter to calculate the result. The result will be the day of the year for the date entered in cell A1.

### Apple Numbers

2. Select the cell where you want to display the day of the year.
3. Type the following formula into the formula bar: =DATEVALUE(A1) - DATEVALUE("1/1/" & YEAR(A1)) + 1, where A1 is the cell containing the date for which you want to calculate the day of the year.
4. Press Enter to calculate the result. The result will be the day of the year for the date entered in cell A1.

### Python

1. Import the datetime module.
2. Create a datetime object for the date for which you want to calculate the day of the year.
3. Use the timetuple() method of the datetime object to get a tuple representing the date.
4. Use the tm_yday attribute of the tuple to get the day of the year.

### JavaScript

1. Use the Date() constructor to create a Date object for the date for which you want to calculate the day of the year.
2. Use the getFullYear() method of the Date object to get the year.
3. Use the getMonth() method of the Date object to get the month.
4. Use the getDate() method of the Date object to get the day of the month.
5. Create a new Date object with the same year, but set the month and day to January 1st.
6. Calculate the number of milliseconds that have passed since the start of the year by subtracting the start of the year Date object from the original Date object and dividing the result by the number of milliseconds per day.
7. Convert the number of milliseconds to the number of days by dividing the number of milliseconds by the number of milliseconds per day.

### PHP

1. Use the date_create() function to create a DateTime object for the date for which you want to calculate the day of the year.
2. Use the date_format() function to get the year, month, and day of the month as integers.
3. Use the date_create() function to create a new DateTime object with the same year, but set the month and day to January 1st.
4. Use the date_diff() function to calculate the difference between the original DateTime object and the start of the year DateTime object.
5. Get the number of days that have passed since the start of the year by using the format() method of the DateInterval object returned by the date_diff() function and passing in the format string "%a". Then, add 1 to the result to get the day of the year, since the day of the year is 1-based (i.e., the first day of the year is day 1).

### MySQL

1. Use the DATE_FORMAT() function to get the year, month, and day of the month as integers.
2. Use the MAKEDATE() function to create a DATE value for the start of the year (January 1st).
3. Use the DATEDIFF() function to calculate the number of days between the original date and the start of the year.

### PostgreSQL

1. Use the date_part() function to get the year, month, and day of the month as integers.
2. Use the date_trunc() function to truncate the original date to the start of the year (January 1st).
3. Use the age() function to calculate the number of days between the original date and the start of the year.