Is it safe to register to vote online, and can I register at any time during the year?

You can register at any time of year. However, in some states, you can't vote until a month after you register, so you have to register at least a month before the election in which you want to vote. You can register during the last month before the election, but you may need to skip that election and wait until the next one to vote.

It depends upon the services of the Election bureau for the country, the state or province or territory, the county or parish or shire, city or town or other governmental district that your residence is in.