How do you manage a sales team that sits across various time zones?

I schedule the team meetings when it is the least impactful to selling time, even if the time isn't ideal for me.  I have an interesting angle on this topic. I used to lead a large sales organization with nearly 1,000 sellers. We did a time study to see how our sales leaders were spending their time over 2 weeks. As the head of sales, I was shocked. They were being asked to be on corporate-led conference calls on all kinds of topics, and these meetings were happening in the middle of the day --- during peak selling time. We mandated that corporate-led conference calls could only be held during specific times. The support leaders were up in arms about it, but it had a significant impact on our sales leaders' productivity and was the right decision.

First you probably need define the process you want them all to follow, them you can automate & digitalize that journey (SalesEnablement, Sales Acivities, customer success). 
If you want them to follow a sales program, you should assess them, train them,  coach them and reward them (keeping in account the different local specificities)

Agree with what has already been posted, it is the tools that enable easy communication, salesforce chatter, webex messenger to ensure the same information is available to all, but they can consume it based on their work schedule.  As a West Coast Leader, with majority of my team in other time zones, I have adjusted my core work schedule to align most closely with the team, I also try and model work-life balance and not work through all time zones to meet the needs of the team.  

There are the "social" aspects, sales people are people, and then the technical aspects of company internal communication. We use every tool under the sun to make it easy for everyone to communicate as needed. Not just one directional from management to sales but the whole network of the company with the sales team. This can be fun, relaxing social engagements on Slack, recorded meetings where important product/company information is being shared, message boards, email, data and document repositories, schedules, calendaring, collaboration tools, a great CRM and so on.

If you hire great salespeople and empower them, remove communication barriers ("open door"/flat hierarchies) this can all play along to help remote folks to stay motivated and engaged. It still means occasional painfully late or early meetings for everyone and it will mean travel for key folks from the HQ to visit, create events, accompany to customers and conferences etc. It is more challenging when the company is small. As it grows there can be trusted managers in better time zones. 

Overall measuring success in sales is easier than elsewhere. A salesperson who does not bring in business and fails to communicate, needs more attention. So it does start with hiring the right people. 

Collaboration tools (I use Teams), Video embedded messages, timezone friendly meetings.