calculating the difference in dates

Dear all,

I attach an excel that contains years and months.

For example the first row reads 2025 7. Today we have 2023 7

I want to calcute in years the difference between the attached dates and the current date (2023 7)

Is there a way to do that in matlab?

Also, I was wondering if it is possible to choose those equipment values that have life less than five years (<5) and life between 5 and 9 [5,9]

Best regards,

Answer 1

[Star Strider]

Try something like this —

T1 = readtable('dates.xlsx', 'VariableNamingRule','preserve')

T1 = 1929×3 table
    Year Built    Month Built    equipment 
    __________    ___________    __________

       2025            7           2.11e+05
       2025            2          1.814e+05
       2025            3           2.07e+05
       2025           10           2.07e+05
       2025            6           1.84e+05
       2024           12         2.1066e+05
       2025            2         2.1066e+05
       2026            8            2.1e+05
       2026           10            2.1e+05
       2025            3            2.1e+05
       2025            6            2.1e+05
       2025            9         2.1063e+05
       2025           12         2.1063e+05
       2026            2         2.1063e+05
       2026            4         2.1063e+05
       1996            3         2.6802e+05

YearMonth = datetime(T1{:,1},T1{:,2}, ones(size(T1{:,1})));                 % Create 'datetime' Array
T1.('Years Difference') = years(YearMonth - datetime(2023,7,1))             % SUbtract Current Year & Month & Add Variable To 'T1'

T1 = 1929×4 table
    Year Built    Month Built    equipment     Years Difference
    __________    ___________    __________    ________________

       2025            7           2.11e+05         2.0014     
       2025            2          1.814e+05         1.5907     
       2025            3           2.07e+05         1.6674     
       2025           10           2.07e+05         2.2533     
       2025            6           1.84e+05         1.9193     
       2024           12         2.1066e+05          1.421     
       2025            2         2.1066e+05         1.5907     
       2026            8            2.1e+05         3.0856     
       2026           10            2.1e+05         3.2526     
       2025            3            2.1e+05         1.6674     
       2025            6            2.1e+05         1.9193     
       2025            9         2.1063e+05         2.1712     
       2025           12         2.1063e+05         2.4203     
       2026            2         2.1063e+05         2.5901     
       2026            4         2.1063e+05         2.7516     
       1996            3         2.6802e+05        -27.333     

The ‘Years Difference’ variable are in decimal fractions of years here. Getting them in units other than hours or days does not appear to be an option.

.

Answer 2

[Rahul]

Hi ektor,

You can try this code,

data = readtable('dates.xlsx'); 

years = data.YearBuilt;
months = data.MonthBuilt;

dates = datetime(years, months, 1);

currentDate = datetime('now');
yearsDiff = year(currentDate) - year(dates);

data.DifferenceInYears = yearsDiff;

writetable(data, 'updated_file.xlsx');

less_than_five = [];
for i = 1:length(data.YearBuilt)
    if(data.DifferenceInYears(i)<5)
       less_than_five = [less_than_five,data.equipment(i)];
    end
end

between_five_and_nine = [];
for i = 1:length(data.YearBuilt)
    if(data.DifferenceInYears(i)>5 && data.DifferenceInYears(i)<9)
       between_five_and_nine = [between_five_and_nine,data.equipment(i)];
    end
end

Please note that if the YearBuilt date is ahead of current DateTime, then it will be taken as negative. If you want it to be reverse or otherwise you can make the required changes to the yearsDiff variable line.

Hope this helps. Thanks.