Since Paragraph 5A, the Delivery of Earnest Money and Option Fee Paragraph, uses the word within when describing the time period, Day One of the option period is the day after the effective date of the contract.

For example, if your client’s effective date is January 22 with a 10-day option period, the option period will end on February 1. If your client wishes to terminate under Paragraph 5B, the Termination Option Paragraph, she must provide notice to the seller by 5 p.m. local time where the property is located on February 1.

It depends on how long the back-up buyer wants to stay in the back-up position. Some back-up buyers may want to have their contract terminate within days if the first contract doesn't terminate early, while others may want to retain their back-up contract rights until after the last possible date that the first contract might close. If your client wants his back-up contract to last until or beyond the first contract's closing date, you can also ask the listing agent to provide the first contract's closing date.

Yes, when calculating deadlines in the One to Four Family Residential Contract (Resale) (TXR 1601, TREC 20-19), use calendar days, not business days, unless the provision specifically states otherwise. For example, when calculating deadlines for the delivery of the earnest money and the option fee, use calendar days. However, the One to Four Family Residential Contract (Resale) allows that if the final day for delivery of those funds falls on a weekend or legal holiday, the deadline is moved to the next day that is not a weekend or legal holiday. The rest of the contract deadlines do not change if the final day falls on a weekend or holiday.