Why Billable Time is twice as long as Run Time.

[hayashi-ay]

Hi, there! This is my first post to this community.

I found Billable Time is twice as long as Run Time. (See the below picture.)

At first I think the core number of the host runner is multiplied but if so mac os would be tripled because macOS virtual machines have 3-core CPU.

I read the documentation, but I can't find a description and I'd like to know why the above result.

Reference

billing result

yml file for the above result

name: test
on:
  push:
    branches: [ "main" ]

jobs:
  linux:
    runs-on: ubuntu-latest
    steps:
      - name: sleep
        shell: bash
        run: sleep 60
  windows:
    runs-on: windows-latest
    steps:
      - name: sleep
        shell: bash
        run: sleep 60
  mac:
    runs-on: macos-12
    steps:
      - name: sleep
        shell: bash
        run: sleep 60

[airtower-luna]

It's described in About billing for GitHub Actions:

GitHub rounds the minutes each job uses up to the nearest minute.

Each of your jobs takes a little over 1 min, so gets rounded up to 2 min. 3 times 2 min makes 6 min.

[hayashi-ay]

Thank you for the quick answer but I think "1m2s" should be 1 minute since the doc says "round" and 1 minute is closer than 2 minutes.

[airtower-luna]

The docs say "rounded up". 😉

[hayashi-ay]

You're right. I need to read docs carefully.

[simplerfid]

For now I can see that rounding works like "rounded up" + 1 min.
For example: duration 4m 23s rouded to 6m.
Such calculation works not for all runs, but for runs with deployment to azure.

[aOverholt]

It seems that every job is rounded up.
I just rewrote our Build and Deploy scripts that deploys to 32 separate s3 buckets. It was all run in one job, so I changed it to run the build job, then run a separate deploy job for each site so they could run asynchronously.
The total run time went from ~15 min to ~3.5 min, but the billable time went from ~15min to 34min because the build job is 2-3 minutes and it's rounding up each of the 30second deploy jobs.