A "next interval" function from Justin Azoff

gistfile1.zeek

function next_interval(i: interval): interval
    {
    local now = current_time();
    local ii = double_to_count(interval_to_double(i));
    local sofar = double_to_count(time_to_double(now)) % ii;
    local togo = ii - sofar;
    local dur = double_to_interval(togo);
    return dur;
    }

print next_interval(60 mins);

Don't forget: "now what people are looking for is"
schedule next_interval(1 hr) { do_that_thing_once_an_hour() };