It gets even more fun if you need to answer questions like: "When this event was scheduled 6 months ago for today at 2pm, what UTC time did that represent then

It gets even more fun if you need to answer questions like: "When this event was scheduled 6 months ago for today at 2pm, what UTC time did that represent then vs now?". Timezone rules also change. So when you're dealing with past and future you might also need the timestamp of the timestamp!