If I get summoned for divorce do I have 30 days after date on paper to respond or does the day I get served count as first day?

The previous answer is correct.  See California Code of Civil Procedure 471.5.  Keep in mind though, that further motions made during the course of this case have a shorter time frame.  Oppositions to motions such as child support, spousal support etc.  made by orders to show cause (OSC) must be responded to by 9 full days before the hearing date.  See California Code of Civil Procedure 1005.

Initially, spousal support is determined by a computer program that compares the incomes of the spouses.  At the first hearing the only evidence heard is a computer printout of a program called Dissomaster.  Later on, the court has more leeway to consider other arguments and determines permanent spousal support under the factors in California Family Code 4320. 

Best of luck.

You have thirty days from the date you were served which would be June 15 to file an answer to the petition for divorce.  You file the answer with the court and serve a copy by mail on your former spouse.  The answer denies the allegations in the petition.  File the answer with a proof of service.  The proof of service verifies the date of mailing to your former spouse.  You can use a court form proof of service or you can write your own proof of service.  If you write your own proof of service, it just says that you are over eighteen and the attached documents were sent via first class mail unless stated otherwise to ___________ (name and address of former spouse) on ___________ (date).  You sign and date at the bottom.  The date you sign should be the same as the mailing date and the same date you file your documents with the court.

If you don't timely file your answer with the court and serve it by mail on your former spouse, your former spouse can have a default judgment entered against you.  A default judgment means you have lost; however, you can still file a motion to set aside the default.  If the court grants your motion to set aside the default, the case will then be back on track and litigation will continue.