Agile/Scrum development is a very collaborative development process. e.g. it requires developers to continuously communicate & work closely together day-in day-out.
How do you handle your "off" days? Those days that you just don't have energy, can't think straight, don't really have anything to say at the standup meetings, etc.
Just like how athletes have their off days.
I don't think there should really be a day where you don't have anything to say at the standup meeting. Every standup meeting should be used to let the rest of the team know whether or not you met the prior day's commitments.
One problem that I have seen on a lot of agile teams is that the developers don't make concrete commitments on a daily basis, so the daily stand-ups aren't all that effective. If that is an issue, make sure everyone in attendance is setting out concrete goals on a daily basis that can objectively be communicated the next day as either done or not done.
To the rest of your question, I think it is perfectly acceptable to go into a daily stand-up and say that you didn't meet the prior day's objective because you had an off day and use the meeting as an opportunity to make new commitments. If there was a reason why you had an off day that could be clearly identified as an impediment (e.g. too many interruption, unclear requirements/objectives, dev environment frustrations), those reasons should be reported to the whomever is leading the stand-ups (scrum master) because it is their responsibility to make sure those impediments are addressed.
If you don't get anything done, say you couldn't focus and didn't get anything done at the standup meeting. The Scrum Master should try to find out of there is some factor that's distracting you, and try to remove it for you.
Also, if these "off days" are semi-frequent occurrences, try to figure out how often they occur, and include them in your estimates. Scrum is about what's really going on. It's about real timelines. If you know you have 4 off days in 4 weeks, then you should only be claiming 4 days a week worth of work, not 5. (That being said, it's possible that what you can do in 4 days is the same as what someone else can do in 5 days).
G'day,
As mkedobbs mentioned, you should mention it in the stand-up meeting.
Maybe you need to look at what's making you have an "off" day and communicate that with your team members.
These are just a few reasons as to why your "off" day may be directly due to your current work. But definitely don't just stay silent though! Mention it at the stand-up so that any potential problems may be addressed sooner rather than later.
HTH
cheers,
Pair programming makes it easier to handle. At least with pair programming, somebody else is there to catch your mistakes early.
Pick a different task/story to work on - so that you get a change on scene. Maybe you've been on the same user story too long.
Gold Cards - (or "fedex days") - where you can work on anything you want: http://www.planningcards.com/iterex/papers/InnovationAndSustainabilityWithGoldCards.pdf What's noticeable about "gold cards" is that the team that introduced them found that they didn't cause a drop in productivity. This would suggest that it's better to take somebody out of the process on an off day and let them do something constructive of their own choosing than let them work unproductively.
I have off days. My team has off days.
If it is happening a lot or if it is the same people, then root cause and action is needed. This might be a good topic for a retrospective if the whole team is affected or one-on-one if it is an individual.
As for the answer, you are part of a team. The team picks up the effort, just like any other issue. If you team has issues with this, you probably don't have a well formed team and just have a bunch of individuals fending for themselves.
Generally at the start of an "off" day, it isn't clear that the day will go badly. It is only after a few stumbles that it becomes clear that it isn't going to be a good day. I'd still try to get something done but sometimes the progress is minuscule. The following day's stand-up is when to say, "Yesterday, I didn't get much done. I had an off day," or something similar to note that I do recognize that things didn't go well and I'd try to do better today.
Sometimes I'd change what I'm doing that day, as that can sometimes help. I have had times where I get a few off days in a row, which generally is indicative of needing to take a personal or vacation day and try to recharge myself to get back in the saddle again.