Can i enter Poland 2 days before my visa start date?

I already received my Poland VISA and I was surprised because that the period of its start at 1/7 and I requested the visa's period to start at 29/6. The first of July it's the first day of my business trip so it's difficult for me to arrive at this day and start work immediately.

My Question is it's possible to enter Poland in 29/6 before 2 days my visa start.

That depends on whether you are from a country whose citizens need a visa in order to enter Poland or not.

Tom Hanks spent seventeen years in a terminal. You can handle two days, surely.

They might be ok about it but it would be taking a risk and it would probably depend on the individual immigration officer.

If your visa is only for work then maybe it is because you aren't technically working until July 1st? If you're from a country that needs a visa to enter, you will be rejected.

Precisely.
And even if he isn't, he will still need to leave Poland and then come back after (or on) the start date of his visa in order for that visa to be valid (I had that problem myself once).

Justly so. Why all this third-world or US immigrants suppose they will get an exception to existing EU/Schengen rules?

Point is if they will inform you at the departure what will be the consequences.Atleast the flghts to the usa and to EU the airlines always inform the security and immigration of the arriving country.Usually they will let you know that you will not be allowed in and can travel at your own risk,I know this as a person who had overstayed in usa 5 years back got the visa but on warsaw airport was told that he wont be allowed in he still took the risk and was deported.I also met a couple jordanian man and american woman in copenhagen transit area where the jordanian man was not being allowed to board the flight for 3 days as the us ICE had refused him entry and airline wont fly him,and his american wife was staying with him in the transit area....I always wonder whatever happened to them.

unfortunately, rules are rules though. perhaps, unless if you're some big shot politician, or star, you may be able to get away with just a few days before entry. but if people know maybe they'll cry fowl. i know, we hate it you hate it but if everybody gets to violate the dates given, then the visa restriction has no meaning. plus, i don't think you really want to mess with the security after what happen to missing planes and things like that. you really don't want to roll the dice and test them.