When should you tell your readers how much time has elapsed after a time skip in a comics?

Question

When should you tell your readers how much time has elapsed after a time skip in a comics? The issue is during a boxing match for example. Sometimes, between panel 4 and panel 5, there's a 20 seconds gap while the other panels have a 3-4 second gap. Should you tell your readers when you just skip 20 seconds forward, or it's ok since 20 seconds is not too long. What should then be the threshold when you should mention how much time has elapsed? 1 hour?

Example:

"Alpha Bravo, tell me if you're detecting any sign of life" said the sergeant as he's running inside a corridor.

"Ok, copy that." said Alpha Bravo.

(5 min after)

"Alpha Bravo, did you find anything?" asked the sergeant as he is seen running inside the corridor still.

Answer 1

If it hasn't been so long for any major developments, I'd suggest you imply that time has passed by changing the setting, the positions of the characters, the amount of work done, etc.

In a screenplay that's how we indicate Sherlock is working hard on a puzzle; he is dissatisfied with something he is writing, crumples up the paper and throws it into a trash can full of other crumpled up pieces of paper. Which implies time passage.

Or we show a montage or superposition shot of our detective thoroughly searching a room (as if there 8 of him looking at various aspects). We don't want it to seem like he magically found the key clue in the room instantly; he worked for it.

We sometimes point at clocks, but it is better to imply the passage of time visually. In your scene, the sergeant is running inside the corridor when he asks his question. Next Panel, just make sure the corridor is noticeably different, or not a corridor at all.

If you really need it to be exactly five minutes, have the sergeant also say, "I'll check back in five."