how can I add add sec, min and hours to time?

I want to add sec, min and hours to a time.

Example:

now it is 07:00:00 am and i would like to add 320 sec to be 07:05:20 am

I try "datenum" but this include a date which I don't want ?

[per isakson]

One way

>> dt = datetime( '07:00:00', 'InputFormat', 'hh:mm:ss' )
dt = 
   2017-11-10 07:00:00
>> dt.Second = dt.Second + 320;
>> dt
dt = 
   2017-11-10 07:05:20
>>

[zeezo]

Thank you very much.

the output comes as a date and time. Can the output time only?

Also it does not work as 24h.

[per isakson]

The secret trick is to read the documentation

>> dt.Format = 'HH:mm:ss';
>> dt.Hour = dt.Hour+12;
>> dt
dt = 
   19:05:20

However, behind the scene there is still a date.

[zeezo]

Can I add AM and PM to the output?

[per isakson]

• Didn't you ask for 24h?
• See datetime, Arrays that represent points in time

[Steven Lord]

The documentation for datetime includes a table of all the letter identifiers that you can use as part of the value for the Format property, and there is an identifier that includes AM or PM in the display. One of the common format examples shows how to use that identifier.

doc datetime

[zeezo]

To clarify what I want:

the time is

23:58:00

and I want to add 320 sec to it. So it should be

00:03:20

[Walter Roberson]

Then use datetime objects and set the Format specification like per showed.

[zeezo]

Thank you Walter.

can you explain in more details?

[Walter Roberson]

dt = datetime( '23:58:00', 'InputFormat', 'HH:mm:ss' );
dt.Format = 'HH:mm:ss';
dt + seconds(320)

ans = 
  datetime
   00:03:20

Answer 1

[KL]

Use duration maybe,

https://www.mathworks.com/help/matlab/ref/duration.html

>> t1 = duration([07 0 0])

t1 = 

    duration

     07:00:00

>> t2 = t1+seconds(320)

t2 = 

    duration

     07:05:20

[zeezo]

Thank you very much.

this does not recognize the duration as a hour for example

>>  t1 = duration([23 58 0])

t1 = 

     23:58:00

>> t2 = t1+seconds(320)

t2 = 

     24:03:20

it add to the duration which makes it more than 23:59:59.

I want it to be 00:03:20

Answer 2

[Felix Bl]

This also works fine:

t1 = datestr(addtodate(datenum('07:00:00','HH:MM:SS'),320,'second'),'HH:MM:SS')