Hi Maksym, if you convert your x vector to a datetime, you can simply plot the datetime vector against your values for the 3 lineplots and already get meaningful labels for the timestamps.
x = today + (0.5:0.01:0.6);
x_datetime = datetime(x, 'ConvertFrom', 'datenum');
As you can see, I start with simple datenum doubles, convert it to datetimes and if you zoom into the plot or use a different time-scale, the x-labels are automatically changed to show meaningful values and details.
If you need the specific format you mentioned, you can specify it with a line like this:
All of this is possible since R2016b or do you need to use an older version of MATLAB?