# What is the standard way to add N seconds to datetime.time in Python?

### Question

Given a `datetime.time` value in Python, is there a standard way to add an integer number of seconds to it, so that `11:34:59` + 3 = `11:35:02`, for example?

These obvious ideas don't work:

``````>>> datetime.time(11, 34, 59) + 3
TypeError: unsupported operand type(s) for +: 'datetime.time' and 'int'
>>> datetime.time(11, 34, 59) + datetime.timedelta(0, 3)
TypeError: unsupported operand type(s) for +: 'datetime.time' and 'datetime.timedelta'
>>> datetime.time(11, 34, 59) + datetime.time(0, 0, 3)
TypeError: unsupported operand type(s) for +: 'datetime.time' and 'datetime.time'
``````

In the end I have written functions like this:

``````def add_secs_to_time(timeval, secs_to_add):
secs = timeval.hour * 3600 + timeval.minute * 60 + timeval.second
return datetime.time(secs // 3600, (secs % 3600) // 60, secs % 60)
``````

I can't help thinking that I'm missing an easier way to do this though.

1
315
5/23/2017 11:47:26 AM

You can use full `datetime` variables with `timedelta`, and by providing a dummy date then using `time` to just get the time value.

For example:

``````import datetime
a = datetime.datetime(100,1,1,11,34,59)
b = a + datetime.timedelta(0,3) # days, seconds, then other fields.
print a.time()
print b.time()
``````

results in the two values, three seconds apart:

``````11:34:59
11:35:02
``````

You could also opt for the more readable

``````b = a + datetime.timedelta(seconds=3)
``````

if you're so inclined.

If you're after a function that can do this, you can look into using `addSecs` below:

``````import datetime

fulldate = datetime.datetime(100, 1, 1, tm.hour, tm.minute, tm.second)
fulldate = fulldate + datetime.timedelta(seconds=secs)
return fulldate.time()

a = datetime.datetime.now().time()
print a
print b
``````

This outputs:

`````` 09:11:55.775695
09:16:55
``````
445
1/15/2013 1:19:11 AM

As others here have stated, you can just use full datetime objects throughout:

``````sometime = get_some_time() # the time to which you want to add 3 seconds
later = (datetime.combine(date.today(), sometime) + timedelta(seconds=3)).time()
``````

However, I think it's worth explaining why full datetime objects are required. Consider what would happen if I added 2 hours to 11pm. What's the correct behavior? An exception, because you can't have a time larger than 11:59pm? Should it wrap back around?

Different programmers will expect different things, so whichever result they picked would surprise a lot of people. Worse yet, programmers would write code that worked just fine when they tested it initially, and then have it break later by doing something unexpected. This is very bad, which is why you're not allowed to add timedelta objects to time objects.