As a general principle, days spent outside of the United States during the validity period of an H-1B petition will not be counted toward the 6-year maximum period of stay in the United States in H-1B status. Any trip of at least one 24-hour day outside the U.S. for any purpose, personal or business, can be recaptured.Detailed documentation that independently corroborates the time spent outside the United States must be presented when filing an I-129 petition that claims recapture time. Note that the burden of proof rests on the H-1B applicant. You must submit a table of time spent outside the US in addition to travel documents, photocopies of passport stamps and/or Form I-94 arrival-departure records, emails from travel agents or airlines, etc to document any and all exact periods of physical presence outside the US. The more clearly the documentation supports any summary statement, the better. Any periods of absence that are claimed, but not corroborated by documentation, will not be counted.
Sample Table Of Days Outside the US
Pages in Passport
Entered Another Country
Departed Other Country
Days Outside the US