Round Datetime to certain minutes

Hey,

I am trying to round an array of datatype datetime to nearest 20 and 50 minutes, e.g. 16:30 - 16:20, 16:54 - 16:50, 16:01 - 15:50, 2020Nov19 00:01 - 2020Nov18 23:50. Does anyone have an idea? I already tried dateshift and interp1.

Your help is highly appreciated.

Answer 1

[dpb]

interp1 will work...

dt=datetime(2020,11,18,00,1+[0:30].',0);        % sample datetime array
dt20=datetime(2020,11,17,0,[20:30:2400].',0);   % 30 min array at 20, 50 past hour

>> interp1(dt20,dt20,dt,'nearest')
ans = 
  31×1 datetime array
   17-Nov-2020 23:50:00
   17-Nov-2020 23:50:00
   17-Nov-2020 23:50:00
   17-Nov-2020 23:50:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
   18-Nov-2020 00:20:00
>> 

There's probably more clever ways...

[Dario Walter]

So close but yet so far. Thank you!