Convert DoY and hour to datetime format

I am very new to matlab and I am working with timeseries data. In the attached example, I want to add a new column as Datetime that displays datetime in the format year, month, day, hour, minute (YYYYMMDDHHMM). Your help will be much appreciated. Thanks.

Year DoY Hour Datetime

2013 1 0.5 201301010030

Answer 1

[Abhishek Tiwari]

Hi,

It can be done by using datetime() with modified display format as demonstrated

T = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1053045/example.xlsx');

T.Datetime = datetime(T.Year, 1, T.DoY, floor(T.Hour), rem(T.Hour, 1).*60, 0, 'format', 'yyyyMMddHHmm')

T = 87648×4 table
    Year    DoY    Hour      Datetime  
    ____    ___    ____    ____________

    2013     1     0.5     201301010030
    2013     1       1     201301010100
    2013     1     1.5     201301010130
    2013     1       2     201301010200
    2013     1     2.5     201301010230
    2013     1       3     201301010300
    2013     1     3.5     201301010330
    2013     1       4     201301010400
    2013     1     4.5     201301010430
    2013     1       5     201301010500
    2013     1     5.5     201301010530
    2013     1       6     201301010600
    2013     1     6.5     201301010630
    2013     1       7     201301010700
    2013     1     7.5     201301010730
    2013     1       8     201301010800

These might be useful:

1. Arrays that represent points in time - MATLAB (mathworks.com)
2. Set Date and Time Display Format - MATLAB & Simulink (mathworks.com)

[Benju Baniya]

Thank you. It worked. This was the exact format I was looking for.

Answer 2

[Eric Sofen]

The datetime constructor is forgiving about day values that don't fit within a particular month and wrapping them appropriately:

t = readtable("https://www.mathworks.com/matlabcentral/answers/uploaded_files/1053045/example.xlsx")

t = 87648×3 table
    Year    DoY    Hour
    ____    ___    ____

    2013     1     0.5 
    2013     1       1 
    2013     1     1.5 
    2013     1       2 
    2013     1     2.5 
    2013     1       3 
    2013     1     3.5 
    2013     1       4 
    2013     1     4.5 
    2013     1       5 
    2013     1     5.5 
    2013     1       6 
    2013     1     6.5 
    2013     1       7 
    2013     1     7.5 
    2013     1       8 

t.DT = datetime(t.Year,1,t.DoY) + hours(t.Hour)

t = 87648×4 table
    Year    DoY    Hour             DT         
    ____    ___    ____    ____________________

    2013     1     0.5     01-Jan-2013 00:30:00
    2013     1       1     01-Jan-2013 01:00:00
    2013     1     1.5     01-Jan-2013 01:30:00
    2013     1       2     01-Jan-2013 02:00:00
    2013     1     2.5     01-Jan-2013 02:30:00
    2013     1       3     01-Jan-2013 03:00:00
    2013     1     3.5     01-Jan-2013 03:30:00
    2013     1       4     01-Jan-2013 04:00:00
    2013     1     4.5     01-Jan-2013 04:30:00
    2013     1       5     01-Jan-2013 05:00:00
    2013     1     5.5     01-Jan-2013 05:30:00
    2013     1       6     01-Jan-2013 06:00:00
    2013     1     6.5     01-Jan-2013 06:30:00
    2013     1       7     01-Jan-2013 07:00:00
    2013     1     7.5     01-Jan-2013 07:30:00
    2013     1       8     01-Jan-2013 08:00:00

% Check that it looks reasonable further along...
t(1000:100:end,:)

ans = 867×4 table
    Year    DoY    Hour             DT         
    ____    ___    ____    ____________________

    2013    21      20     21-Jan-2013 20:00:00
    2013    23      22     23-Jan-2013 22:00:00
    2013    26       0     26-Jan-2013 00:00:00
    2013    28       2     28-Jan-2013 02:00:00
    2013    30       4     30-Jan-2013 04:00:00
    2013    32       6     01-Feb-2013 06:00:00
    2013    34       8     03-Feb-2013 08:00:00
    2013    36      10     05-Feb-2013 10:00:00
    2013    38      12     07-Feb-2013 12:00:00
    2013    40      14     09-Feb-2013 14:00:00
    2013    42      16     11-Feb-2013 16:00:00
    2013    44      18     13-Feb-2013 18:00:00
    2013    46      20     15-Feb-2013 20:00:00
    2013    48      22     17-Feb-2013 22:00:00
    2013    51       0     20-Feb-2013 00:00:00
    2013    53       2     22-Feb-2013 02:00:00

[Benju Baniya]

Thank you. It worked.