Day of year conversion

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I am looking for a conversion calendar on this website that is similar to the one on NASA's site that they call "Day of Year Calendar"

Despite the "Julian Date" in the link on the NASA site (not posted here as i am a noob),

"Note that Julian date is sometimes used as a synonym for day of year, but this is not correct usage. Day of year ranges from 1 to 365 (366 for leap years) whereas Julian dates (abbreviated JD) are a continuous count of days and fractions since noon Universal Time on January 1, 4713 BCE (on the Julian calendar). Julian dates are widely used as time variables within astronomical software and should not be confused with day of year."

I am looking for a Day of Year convertor on this site so I can get the created dates on many food products.

Thank you in advance.

[JohnS]

Re: Day of year conversion

I am looking for a conversion calendar on this website that is similar to the one on NASA's site that they call "Day of Year Calendar"

Despite the "Julian Date" in the link on the NASA site (not posted here as i am a noob),

"Note that Julian date is sometimes used as a synonym for day of year, but this is not correct usage. Day of year ranges from 1 to 365 (366 for leap years) whereas Julian dates (abbreviated JD) are a continuous count of days and fractions since noon Universal Time on January 1, 4713 BCE (on the Julian calendar). Julian dates are widely used as time variables within astronomical software and should not be confused with day of year."

I am looking for a Day of Year convertor on this site so I can get the created dates on many food products.

Thank you in advance.

This calculator
http://www.onlineconversion.com/day_week_number.htm
takes date as input and gives ordinal day, week number and day of week

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Re: Day of year conversion

Thanks for very fast reply, but I am looking to convert from the other direction, as many food manufacturers print "day of the year/year" on their packaging, i.e., 274/13 for Oct 1, 2013.

Happy July 4th,
God Bless America

[JohnS]

Re: Day of year conversion

Thanks for very fast reply, but I am looking to convert from the other direction, as many food manufacturers print "day of the year/year" on their packaging, i.e., 274/13 for Oct 1, 2013.

Happy July 4th,
God Bless America

Not a calculator, but this table will do the job for you:
http://www.atmos.anl.gov/ANLMET/OrdinalDay.txt

[JohnS]

No calculator, but the following pseudo-code works in any computer language or calculator. Result of each step for your example follows in parentheses, Day of Year = doy
1. IF y is a leap year, THEN IsLeap = 1, ELSE IsLeap = 0. (0)
2. IF doy > 59 +IsLeap, THEN k = 2 - IsLeap, ELSE k = 0. (1)
3. x = doy + 30 + k. (306)
4. m = INT(16*x/489). (10)
5. d = x - INT(489*m/16). (1)
m,d are month and day

Variants: If you use integer divides (\), you can eliminate the integer function. On a calculator, using reals, you may use INT(0.03272*x) and INT(30.56*m) in steps 4 & 5.