How to extract date, month, year, and time from a table data?

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I have a table data like "A" like this:
>> A(1:49,1)
ans =
49×1 table
DateTime
___________________
2016-01-01 00:30:00
2016-01-01 01:00:00
2016-01-01 01:30:00
2016-01-01 02:00:00
2016-01-01 02:30:00
2016-01-01 03:00:00
2016-01-01 03:30:00
2016-01-01 04:00:00
2016-01-01 04:30:00
2016-01-01 05:00:00
2016-01-01 05:30:00
2016-01-01 06:00:00
2016-01-01 06:30:00
2016-01-01 07:00:00
2016-01-01 07:30:00
2016-01-01 08:00:00
2016-01-01 08:30:00
2016-01-01 09:00:00
2016-01-01 09:30:00
2016-01-01 10:00:00
2016-01-01 10:30:00
2016-01-01 11:00:00
2016-01-01 11:30:00
2016-01-01 12:00:00
2016-01-01 12:30:00
2016-01-01 13:00:00
2016-01-01 13:30:00
2016-01-01 14:00:00
2016-01-01 14:30:00
2016-01-01 15:00:00
2016-01-01 15:30:00
2016-01-01 16:00:00
2016-01-01 16:30:00
2016-01-01 17:00:00
2016-01-01 17:30:00
2016-01-01 18:00:00
2016-01-01 18:30:00
2016-01-01 19:00:00
2016-01-01 19:30:00
2016-01-01 20:00:00
2016-01-01 20:30:00
2016-01-01 21:00:00
2016-01-01 21:30:00
2016-01-01 22:00:00
2016-01-01 22:30:00
2016-01-01 23:00:00
2016-01-01 23:30:00
2016-01-02 00:00:00
2016-01-02 00:30:00
This is a very large array containing time stamp for every half hour interval for 2 year duration. I wanted to extract the year (say 2016), day (say 1), month (say 1), and time (say 00:30 as 0.5) from this table data. How to do the same? Kindly help me.

Answers (2)

VBBV
VBBV on 19 Dec 2022
Edited: VBBV on 19 Dec 2022
A = string({'2016-01-09 00:30:00';'2017-05-10 01:00:00'});
At = table(A,'VariableNames',{'Time'});
for k = 1:length(At.Time)
Y(k) = datetime(At.Time(k),'Format','yyyy'); % year
M(k) = datetime(At.Time(k),'Format','MM'); % month
D(k) = datetime(At.Time(k),'Format','dd'); % day
H(k) = datetime(At.Time(k),'Format','hh:mm'); % time
end
Y, M, D , H
Y = 2×1 datetime array
2016 2017
M = 1×2 datetime array
01 05
D = 1×2 datetime array
09 10
H = 1×2 datetime array
12:30 01:00
  1 Comment
Stephen23
Stephen23 on 19 Dec 2022
Edited: Stephen23 on 19 Dec 2022
This code simply changes the formatting, but the underlying date/time data is still stored in the DATETIME object. So it does not actually "extract the year ... day .. month ... and time ... from this table data", it just changes how the DATETIME object is displayed.

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Stephen23
Stephen23 on 19 Dec 2022
Edited: Stephen23 on 19 Dec 2022
The MATLAB approach is to use YMD() and TIMEOFDAY() and HOURS():
S = ["2016-01-01 00:30:00"; "2016-01-01 01:00:00"; "2016-01-01 01:30:00"; "2016-01-01 02:00:00"; "2016-01-01 02:30:00"; "2016-01-01 03:00:00"; "2016-01-01 03:30:00"];
T = datetime(S)
T = 7×1 datetime array
01-Jan-2016 00:30:00 01-Jan-2016 01:00:00 01-Jan-2016 01:30:00 01-Jan-2016 02:00:00 01-Jan-2016 02:30:00 01-Jan-2016 03:00:00 01-Jan-2016 03:30:00
[Y,M,D] = ymd(T)
Y = 7×1
2016 2016 2016 2016 2016 2016 2016
M = 7×1
1 1 1 1 1 1 1
D = 7×1
1 1 1 1 1 1 1
H = hours(timeofday(T))
H = 7×1
0.5000 1.0000 1.5000 2.0000 2.5000 3.0000 3.5000

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