Does 20 days less experience than mentioned in walkin matter ?

I attended CTS walkin and got selected, they conducted walkin for 18 months to 34 months and above professionals. I mentioned only the month of joining and resigning from my previous company in my resume, so they did not know my experience exactly.I have 20 days less of 18 months experience.Does this have any effect on background verification?

Sorry, probation period was for 1 year...

These factors are easily explainable to the new employer.
In BGV all these factors will get revealed.
But your explanation will be logical-probation period and that yuo left for new job from probation itself.

thank you for your reply nathrao..
The exact situation is that I have 17 months and 10 days experience from my previous employer.I have mentioned in my resume that i have 18 months experience.Now i got the offer letter and in the Background verification I gave my joining and releiving date.... it is showing that i am 20 days less..
I wanted to know if 20 days really matters,,,will they consider me for this job...? Is this a serious issue...?? I just rounded off 17 months 1o days to 18 months..

It all depends on how many people attend the walk in.
20 days rounding off should not be such a big issue.

Dear Kapil:
A few days more, or a few days less, don't really matter. What does count at a walk-in is how street-smart you were in the 'communication exchange', how alert, yet relaxed, you were, what your level of confidence was coupled with your presence of mind in a stressful situation.
Hope this helps
Arif ur Rehman