missing decima using 'datetime' function

Hi:

I tried to use command below to convert string to datetime, however, the result is :

27-Jun-2023 16:20:00

instead of the expected:

27-Jun-2023 16:20:00:036

datetime({'2023-06-27 16:20:00:036'},'InputFormat','yyyy-MM-dd HH:mm:ss:SSS','TimeZone','America/New_York')

is there any mistake with my command?

Thanks!

Yu

Answer 1

[Steven Lord]

No, there's no mistake, but there is a piece missing. Specifying the InputFormat when you construct a datetime only controls how the input data is interpreted. It does not affect how the resulting datetime is displayed. For that you need to set the Format of the datetime. If you want the data to be displayed the same way it was interpreted, specify the same format for both InputFormat and Format.

fmt = 'yyyy-MM-dd HH:mm:ss:SSS';
dt = datetime({'2023-06-27 16:20:00:036'}, ...
    'InputFormat',fmt, ...
    'Format', fmt, ...
    'TimeZone','America/New_York')

dt = datetime
   2023-06-27 16:20:00:036

Or you can set the Format property of the datetime after it is created.

dt2 = datetime({'2023-06-27 16:20:00:036'},'InputFormat',fmt,'TimeZone','America/New_York')

dt2 = datetime
   27-Jun-2023 16:20:00

dt2.Format % Note this is not the same as fmt; it doesn't include fractional seconds

ans = 'dd-MMM-uuuu HH:mm:ss'

dt2.Format = fmt % Set the Format on the already created datetime

dt2 = datetime
   2023-06-27 16:20:00:036

In any case, this is a display issue; even if the datetime doesn't show that it has the fractional seconds, it does as you can see by asking for the seconds component of the datetime.

dt3 = datetime({'2023-06-27 16:20:00:036'},'InputFormat',fmt,'TimeZone','America/New_York')

dt3 = datetime
   27-Jun-2023 16:20:00

second(dt3)

ans = 0.0360

[Yu Li]

thank you very much!