Global Event Time Broadcaster
Score how well a UTC broadcast time serves your primary global audience. Use it when planning webinars, live streams, or product launches to maximize viewer convenience across time zones.
About this calculator
Scheduling a live global event involves balancing the convenience of audiences scattered across many time zones. This calculator produces a 0–100 convenience score based on how close the event lands to a target prime-time hour (19:00 local) for your primary audience. The formula is: score = max(0, 100 − |((event_hour + primary_audience_zone) − 19)| × 8 × audience_distribution × weekend_penalty − event_duration × 2). Each hour away from 19:00 local time deducts points, scaled by how concentrated your audience is (audience_distribution) and whether the event falls on a weekend (weekend_penalty > 1). A longer event also reduces the score slightly because it encroaches on late or early hours for fringe viewers. The goal is to maximise the score by shifting the UTC broadcast hour until the primary audience's local time is closest to prime time.
How to use
Suppose you plan a 2-hour webinar at 14:00 UTC targeting a US Eastern audience (UTC−5). Set event_hour = 14, event_duration = 2, primary_audience_zone = −5, audience_distribution = 1.0, weekend_penalty = 1.0. Local time for the audience = 14 + (−5) = 9:00. Score = max(0, 100 − |(9 − 19)| × 8 × 1.0 × 1.0 − 2 × 2) = max(0, 100 − 10 × 8 − 4) = max(0, 100 − 80 − 4) = 16. A score of 16 reflects that 09:00 is far from evening prime time. Shifting the event to 22:00 UTC (17:00 local) would raise the score significantly closer to 100.
Frequently asked questions
How do I choose the best UTC time to broadcast a live event for a global audience?
Start by identifying your primary audience's time zone and target a local broadcast time around 18:00–20:00, which consistently shows the highest engagement for live online events. Convert that ideal local time back to UTC by subtracting the UTC offset. If you have secondary audiences, check their local equivalents and look for a UTC hour that keeps everyone within a reasonable window. This calculator's score helps you compare candidate UTC times at a glance without manual conversion for each region.
What is a good convenience score for a global broadcast event?
Scores above 70 indicate that the event falls comfortably within prime evening hours for the primary audience with minimal duration penalty. Scores between 40 and 70 suggest the event is viewable but not ideal — perhaps early morning or late afternoon for some segments. Below 40, a significant portion of your target audience will find the timing inconvenient, and you should consider offering a replay or scheduling a second broadcast for a different region. There is rarely a single UTC time that scores above 80 for audiences spread across more than 6 time zones simultaneously.
Why does event duration affect the global broadcast convenience score?
A longer event extends into hours that may be acceptable at its start time but become inconvenient as it runs. A 4-hour broadcast starting at a reasonable local time can still push into midnight for your audience. The formula deducts 2 points per hour of duration as a proxy for this creep effect. For multi-hour events, consider breaking them into sessions broadcast at different UTC times, or recording key segments for regional replay to protect your convenience score.