What WhatsApp is for, when the customer is in San Jose
For a US number, WhatsApp is a service and update channel. A customer in San Jose can write to you and get a free-form reply for 24 hours. You can send utility templates about their own account or order, and authentication templates with sign-in codes. What you cannot do is send a marketing template: Meta does not deliver them to US numbers, so they simply fail.
That changes how an Indian team plans. Product news, offers and festival greetings for US customers go by email or inside your product; WhatsApp carries the order, the invoice, the ticket and the answer. A utility template that slips in promotional wording is reclassified as marketing by Meta and stops arriving too.
The clock is the other constraint. San Jose keeps Pacific Standard Time, UTC−8, from the first Sunday in November to the second Sunday in March, and Pacific Daylight Time, UTC−7, the rest of the year. India is thirteen and a half hours ahead in winter and twelve and a half in summer, so a San Jose working morning is an Indian late evening.