Will I have a visa problem?

Assuming that you're asking about Schengen: Nope, not at entry: a. The chance of anybody asking for a ticket is slim to zip. b. At the moment of entry you have not broken any rules in that you're free to reschedule your departure. What may/could happen at the time of departure is a different story since, at that point, you would have sinned. It would seem that in three months you could slip into a non-Schengen country for a couple or three days.

Thanks for your speedy reply. What would it take for it not to be a problem?

Simple. Go to a non-Schengen country for three days or so. Odds are that if you're going for three months, you probably have England of the list so the problem is solved. Ireland would do the same trick. So would Morocco. The essence is that the visa is not a 'europe visa' it's a common visa for twenty-six specific nations.

I see that the UK and Ireland are not required to implement the Schengen rule. So since I'm flying into Ireland and spending 3 days there, there should be no problem. Thanks for alerting me to that!

Just keep proof of your stay outside the Schengen zone. Stamps in your passport are good, but hotel receipts would also show that you've not stayed the entire time in the zone. Just in case they ask.

90 days is the rule. But is seems to me that nobody cares. My sister just spent half year in the Czech Republic. I was little concerned but she had absolutely no problems when departing.

Whoa! The last posting can lead some astray. They DO care, and they can fine you big time (my daughter was fined 500 Euros for overstaying 3 days). And, they threatened her with the other punishments they can mete out: refusing entry into the Schengen area for up to 10 years; they kept her waiting for a long time and she almost missed her flight. They could have then forced her to buy a ticket again and send her packing. It really depends on the officials you encounter on leaving. We have friends who have had even worse experiences at the airport in Berlin. By arriving in Ireland you're going to be OK, but, dear readers, don't assume since one person hasn't been hassled you won't. The downside can be quite nasty.

It seems your problem is solved by beginning in Ireland. I think it depends on the length of your overstay and the luck of which government agent you get.