Timestamp in table not recognized as time value

Hello,

I have the following data time format in a table

'2020-08-03T20:40:00.000Z'

When I try to plot this data with another variable. I get the following message:

Error using scatter (line 54)

Input arguments must be numeric, datetime, duration or categorical.

I am aware that one can remove the T and the Z, in the following manner:

wtg_ref.Timestamp = strrep(wtg_ref.Timestamp, 'T', ' ');

wtg_ref.Timestamp = strrep(wtg_ref.Timestamp, 'Z', '');

However, that does and would not help either. It seems the value in the cell is not treated as time. A clue might be that the time value has quotation marks around it in the cells...

It would, of course be easier, to keep the T and Z in the format.

Support would be very much appreciated. Thank you.

[Malik]

I should mention, I also tried: time = datenum('2020-08-01T04:26:18.887Z','yyyy-mm-ddTHH:MM:SS.FFFZ');

But then I lose the milliseconds when I datestr(result)

Answer 1

[Star Strider]

It likel;y needs to be converted to a datetime array —

timestamp = '2020-08-03T20:40:00.000Z'

timestamp = '2020-08-03T20:40:00.000Z'

datetimestamp = datetime(timestamp, 'InputFormat','yyyy-MM-dd''T''HH:mm:ss.SSS''Z''', 'TimeZone','UTC')

datetimestamp = datetime
   03-Aug-2020 20:40:00

The desired 'Format' and time zone in the code can be whatever you want.

datetimestamp.Format = 'yyyy-MMM-dd HH:mm:ss.SSS'

datetimestamp = datetime
   2020-Aug-03 20:40:00.000

datetimestamp.TimeZone = 'UTC-7'

datetimestamp = datetime
   2020-Aug-03 13:40:00.000

The actual format of the month and day are a bit ambiguous, so change those if they are not as I defined them in 'InputFormat'.

.

[Malik]

Hey Star Rider,

Thanks for coming to the rescue :-)

I am sorry, I can't manage to get the milliseconds with the above - It is probably me not following...

I have now tried the following as workaround:

old = '2020-08-03T20:40:00.111Z';

new = strrep(old, 'T', ' ');

new = strrep(new, 'Z', '')

time = datetime(new,'Format','yyyy-MM-dd HH:mm:ss.SSS')

And that gives the desired milliseconds

time = 2020-08-03 20:40:00.111

I would rather do it a more 'correct' or 'efficient' manner. If you could please advice.

Thanking you in anticipation.

[Star Strider]

I do not understand the problem you are having with my code.

Please do not use the strrep calls, since they are not necessary. The 'InputFormat' string I use in my code correctly interprets the ‘T’ and ‘Z’ and produces the correct conversion.

A one-line version of my code, adding a new value to ‘old’ to demonstrate that it works with column vectors:

old = {'2020-08-03T20:40:00.111Z'; '2020-08-03T20:40:01.123Z'};
time = datetime(old, 'InputFormat','yyyy-MM-dd''T''HH:mm:ss.SSS''Z''', 'TimeZone','UTC', 'Format','yyyy-MMM-dd HH:mm:ss.SSS')

time = 2×1 datetime array
   2020-Aug-03 20:40:00.111
   2020-Aug-03 20:40:01.123

It produces thae appropriate datetime values. (That does everything except the time zone conversion to a different time zone that I originally posted, and that is not absolutely necessary.)

.

[Malik]

Thank you Star Strider! You a star!

Apologies, for the delay in response to get back to this. Was fixing another bit of code!

[Star Strider]

As always, my pleasure! Thank you!

No worries! We all have lives outside of MATLAB Answers!

[Xiaoqi Davey]

Star Strider is the man!

[Star Strider]

@Xiaoqi Davey — Thank you!!

A Vote would be appreciated!