How long do you have to respond (if at all) to a modification to a divorce once served?

For future reference, this information can be found on the citation provided to you when you were served. The answer is “on or before 10:00 a.m. on the Monday next after the expiration of twenty days after the date of service.” There are numerous answer date calculators available online to assist you with this. However, I don't know how accurate these are, so I would check more than one and hire an attorney ASAP. Best of luck to you!

Take the documents to family law counsel. The answer time is 20 days following the Monday from the date of service at 10 a.m. The calculation can be tricky but basically can be any period between 21 and 27 days from date of service. But you need to know what to file as well as when to file -- some filings like transfers must be filed as first pleading. Take papers to family law counsel. Do not it DIY this. Also if a show cause or temporary orders' hearing is set you have a different time for response or appearance to that. Take papers to family law counsel ASAP is your best answer.

If you want to request affirmative relief from the court (such as your own requested modification), you need to file a Counter-Petition. As indicated in the other responses, the time period to respond can be different depending on what needs to be done. Best of Luck.