You can call the network of volunteers as often as you wish and at any time of the day. There are no limits to the length of calls, but as the volunteers answer calls as they go about their daily lives, they might have time restraints. It is therefore appreciated that you inform the volunteer, if you know a task might take a long time. Remember that you can always call another volunteer, if the first one has to go. A lot of blind users opt to splitting long tasks into smaller bits and calling different volunteers for each bit.
Calling Specialized Help companies
You can call the Specialized Help companies as often as you wish within their opening hours. As calls to Specialized Help companies often deal with more complex issues, these calls tend to be longer than calls to volunteers. There are no limit to the length of the calls, but depending on the company, they might have limited available agents.