# How to find a list of dates from a timetable?

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Ashfaq Ahmed on 15 Feb 2023
Answered: Seth Furman on 14 Mar 2023
Hi!
I have a long timetable (Date_Captured.mat, attched) that contains 28805 different dates.
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I want to find out specific 764 dates (Date_to_find.mat, attched) from the timetable.
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Can anyone please tell me how can I do that?

Star Strider on 15 Feb 2023
Try this —
Date_Captured = LD1.Date_Captured
Date_Captured = 28805×2 timetable
TimeSeries HourSeries HeightSeries ___________ __________ ____________ 01-Jan-1984 {'09:00'} 0.216 01-Jan-1984 {'10:00'} 0.487 02-Jan-1984 {'09:00'} -0.009 02-Jan-1984 {'10:00'} 0.279 03-Jan-1984 {'09:00'} -0.186 03-Jan-1984 {'10:00'} 0.066 04-Jan-1984 {'09:00'} -0.313 04-Jan-1984 {'10:00'} -0.108 05-Jan-1984 {'09:00'} -0.408 05-Jan-1984 {'10:00'} -0.239 06-Jan-1984 {'09:00'} -0.479 06-Jan-1984 {'10:00'} -0.338 07-Jan-1984 {'09:00'} -0.514 07-Jan-1984 {'10:00'} -0.41 08-Jan-1984 {'09:00'} -0.494 08-Jan-1984 {'10:00'} -0.448
Date_to_find = LD2.Date_to_find
Date_to_find = 764×2 timetable
Time Var1 Var2 __________ _____ _____________ 1984-05-02 0.12 {'landsat_5'} 1984-06-03 18.49 {'landsat_5'} 1984-06-19 0 {'landsat_5'} 1984-09-23 1.49 {'landsat_5'} 1984-10-09 47.1 {'landsat_5'} 1984-10-25 7.27 {'landsat_5'} 1984-11-10 46.36 {'landsat_5'} 1984-11-26 0.08 {'landsat_5'} 1985-01-29 0.11 {'landsat_5'} 1985-04-19 71.61 {'landsat_5'} 1985-06-22 1.53 {'landsat_5'} 1985-08-09 0 {'landsat_5'} 1985-10-12 0 {'landsat_5'} 1985-10-28 0 {'landsat_5'} 1986-01-16 16.37 {'landsat_5'} 1986-02-01 43.73 {'landsat_5'}
[yc,mc,dc] = ymd(Date_Captured.TimeSeries);
[yf,mf,df] = ymd(Date_to_find.Time);
Lv = ismember([yc,mc,dc],[yf,mf,df],'rows');
Hits = nnz(Lv)
Hits = 1539
Result = Date_Captured(Lv,:)
Result = 1539×2 timetable
TimeSeries HourSeries HeightSeries ___________ __________ ____________ 02-May-1984 {'09:00'} -0.428 02-May-1984 {'10:00'} -0.224 03-Jun-1984 {'09:00'} -0.535 03-Jun-1984 {'09:30'} -0.51 03-Jun-1984 {'10:00'} -0.485 19-Jun-1984 {'09:00'} -0.338 19-Jun-1984 {'10:00'} -0.39 19-Jun-1984 {'10:24'} -0.3755 23-Sep-1984 {'09:00'} 0.401 23-Sep-1984 {'10:00'} 0.646 23-Sep-1984 {'10:54'} 0.673 09-Oct-1984 {'09:00'} 0.026 09-Oct-1984 {'10:00'} 0.283 25-Oct-1984 {'09:00'} -0.217 25-Oct-1984 {'10:00'} 0.154 10-Nov-1984 {'09:00'} -0.224
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##### 2 CommentsShow 1 older commentHide 1 older comment
Star Strider on 15 Feb 2023
Thank you!

Sulaymon Eshkabilov on 15 Feb 2023
An alternative solution:
D2_Date = datetime(D2.Time, 'Format','dd-MMM-uuuu');
DIF_DATES = intersect(D1.TimeSeries, D2_Date);
DALL = D1.TimeSeries(DIF_DATES) % All selected dates
DALL = 1539×1 datetime array
02-May-1984 02-May-1984 03-Jun-1984 03-Jun-1984 03-Jun-1984 19-Jun-1984 19-Jun-1984 19-Jun-1984 23-Sep-1984 23-Sep-1984 23-Sep-1984 09-Oct-1984 09-Oct-1984 25-Oct-1984 25-Oct-1984 10-Nov-1984 10-Nov-1984 26-Nov-1984 26-Nov-1984 29-Jan-1985 29-Jan-1985 19-Apr-1985 19-Apr-1985 22-Jun-1985 22-Jun-1985 22-Jun-1985 09-Aug-1985 09-Aug-1985 12-Oct-1985 12-Oct-1985
DS_DATA = D1(DIF_DATES, :) % All selected data w.r.t the selected dates
DS_DATA = 1539×2 timetable
TimeSeries HourSeries HeightSeries ___________ __________ ____________ 02-May-1984 {'09:00'} -0.428 02-May-1984 {'10:00'} -0.224 03-Jun-1984 {'09:00'} -0.535 03-Jun-1984 {'09:30'} -0.51 03-Jun-1984 {'10:00'} -0.485 19-Jun-1984 {'09:00'} -0.338 19-Jun-1984 {'10:00'} -0.39 19-Jun-1984 {'10:24'} -0.3755 23-Sep-1984 {'09:00'} 0.401 23-Sep-1984 {'10:00'} 0.646 23-Sep-1984 {'10:54'} 0.673 09-Oct-1984 {'09:00'} 0.026 09-Oct-1984 {'10:00'} 0.283 25-Oct-1984 {'09:00'} -0.217 25-Oct-1984 {'10:00'} 0.154 10-Nov-1984 {'09:00'} -0.224
numel(DS_DATA(:,1)) % Number of selected data points/pairs
ans = 1539
Ashfaq Ahmed on 17 Feb 2023
Great code!

Seth Furman on 14 Mar 2023
You can index into a timetable more concisely by simply passing the target row-times as row indices.
Shift all row-times to the start of the current date
(This step is unnecessary if you already know that your datetimes have zeroes for hours, minutes, seconds, etc.)
Date_Captured.Properties.RowTimes = dateshift(Date_Captured.Properties.RowTimes,"start","day","current");
Date_to_find.Properties.RowTimes = dateshift(Date_to_find.Properties.RowTimes,"start","day","current");
Index the timetable by the target row-times
Date_Captured(Date_to_find.Properties.RowTimes,:)
ans = 1539×2 timetable
TimeSeries HourSeries HeightSeries ___________ __________ ____________ 02-May-1984 {'09:00'} -0.428 02-May-1984 {'10:00'} -0.224 03-Jun-1984 {'09:00'} -0.535 03-Jun-1984 {'09:30'} -0.51 03-Jun-1984 {'10:00'} -0.485 19-Jun-1984 {'09:00'} -0.338 19-Jun-1984 {'10:00'} -0.39 19-Jun-1984 {'10:24'} -0.3755 23-Sep-1984 {'09:00'} 0.401 23-Sep-1984 {'10:00'} 0.646 23-Sep-1984 {'10:54'} 0.673 09-Oct-1984 {'09:00'} 0.026 09-Oct-1984 {'10:00'} 0.283 25-Oct-1984 {'09:00'} -0.217 25-Oct-1984 {'10:00'} 0.154 10-Nov-1984 {'09:00'} -0.224