Regarding Days to month

I have some data from 2008-2011, which includes leap year 2008. my data sets has following values [year day hour ]

I have days in each year ( 1:365 or 1:366), i wanna to calculate the months.

Thank you

Answer 1

[Jan]

Standard:

datevec(datenum(2008, 1, 12))
>> [2008, 1, 12, 0, 0, 0]

Automatic months overflow:

datevec(datenum(2008, 1, 32))
>> [2008, 2, 1, 0, 0, 0]

Considers leap year:

datevec(datenum(2008, 1, 60))
>> [2008, 2, 29, 0, 0, 0]
datevec(datenum(2008, 1, 61))
>> [2008, 3, 1, 0, 0, 0]

[Uday]

Thank you for reply

but my question was little bit different

As I mentioned earlier I have data sets [ Year Days Hour], but I need months from days( so I can calculate fraction year from that).

Days are in the range of 1:365 and 1:366(leap year, 2008).

I have already tried these datevec and datenum function.

[Oleg Komarov]

And how the automatic month overflow that Jan shows doesn't solve your problem? Have you tried it?

[Jan]

@Pimple: I do not see the differnce. Let [Day] be the day number in the range 1:356 or 366. Then this gets the corresponding month: "D = datevec(datenum(Year, 1, Day, Hour, 0, 0)); Month=D(2)".

If this still does not help, please explain the wanted output exactly again.

Answer 2

[the cyclist]

I would expect you to be able to accomplish what you want with some combination of the command datevec(), datenum(), and datestr(). If you can't figure it out, post the exact format of what you have, and what you want as output. Show us the code that you have tried yourself.

Answer 3

[Walter Roberson]

T = datevec(datenum(YourYear, 1, YourDays, YourHours, 0, 0));
TheMonth = T(:,2)

But if you want to calculate fraction of a year, you do not need to calculate the month number:

YearFraction = datenum(YourYear, 1, YourDays, YourHours, 0, 0) - datenum(YourYear, 1, 1, 0, 0, 0);

[Uday]

I used fractYear=year+ ((day-1)+(hour/24))./(365+(eomday(year,2)==29));

it works fine.

[Jan]

@Pimple: I can see just a weak connection to your statement "i wanna to calculate the months". Please save our time by asking more precisely.