Date time conversion fail

Hello all,

I would like to conver a time to num format so i can do some basic math on it and then I wold like to format t back to day time format.

TimeFormat = 'yyyymmddHHMMSS';

st_file=cell(1,1);%Memory prealocation
t = w_files{2,1}(1,"time") %I am pulling a time from my data: 2022-08-08 10:18:12.000

t =

  table

             time          
    _______________________

    2022-08-08 10:18:12.000
    
t = table2array(t)%Converting it to cell because datestr does not work as it is right now

t = 

  datetime

   2022-08-08 10:18:12.000
   
   
t = datestr(t,TimeFormat);%Making it a str

t =

    '20220808101812'
    
    
t = datetime(t,"InputFormat",TimeFormat)%Changing it back to date time format

t = 

  datetime

   08-Oct-2020 08:22:00

Is this how is the sotware intended to work? Where am I making a mistake and how can I avoid it in the future. Thanks!

Answer 1

[Karim]

From the looks of it, you need to change the months (M) and minutes (m) symbols in your time format to convert the string into expected datetime. See below:

TimeFormat = 'yyyyMMddHHmmSS';

t = "20220808101812"

t = "20220808101812"

t = datetime(t,"InputFormat",TimeFormat)

t = datetime
   08-Aug-2022 10:18:00

[Karel Starý]

This works. After s gooli found out that date format is different for "datestr" function and "datetime" func. Wat a beatifull way to write a software, right :D

Thans anyway!

[Walter Roberson]

datetime() was written using ISO standard codes for date and time. datestr() is older than the ISO standard.

Answer 2

[Steven Lord]

I would like to conver a time to num format so i can do some basic math on it

What math do you want to do to the time data? There may be a way to avoid converting from time to number and back. For example:

T = datetime('today')

T = datetime
   29-Aug-2022

nextMonth = T + calmonths(1)

nextMonth = datetime
   29-Sep-2022

startOfThisMonth = dateshift(T, 'start', 'month')

startOfThisMonth = datetime
   01-Aug-2022