Get current date and time in GitHub workflows

I have a GitHub workflow for releasing nightly snapshots of the repository. It uses the create-release action. This is how the workflow file looks right now:

name: Release Nightly Snapshot

on:
  schedule:
  - cron: "0 0 * * *"

jobs:
  build:
    name: Release Nightly Snapshot
    runs-on: ubuntu-latest
    steps:
      - name: Checkout master Branch
        uses: actions/checkout@v2
        with:
          ref: 'master'
      - name: Create Release
        id: nightly-snapshot
        uses: actions/create-release@latest
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          tag_name: 'nightly snapshot'
          release_name: 'nightly snapshot'
          draft: false
          prerelease: false

I want tag_name and release_name to use the current date and time, instead of hard-coded values. However, I couldn't find any documentation on it. How should I do it?

From this post you can create a step that set its output with the value $(date +'%Y-%m-%d')

Then use this output using ${{ steps.date.outputs.date }}. The following show an example for environment variables and for inputs :

on: [push, pull_request]
name: build
jobs:
  build:
    name: Example
    runs-on: ubuntu-latest
    steps:
      - name: Get current date
        id: date
        run: echo "::set-output name=date::$(date +'%Y-%m-%d')"
      - name: Test with environment variables
        run: echo $TAG_NAME - $RELEASE_NAME
        env:
          TAG_NAME: nightly-tag-${{ steps.date.outputs.date }}
          RELEASE_NAME: nightly-release-${{ steps.date.outputs.date }}
      - name: Test with input
        uses: actions/hello-world-docker-action@master
        with:
          who-to-greet: Mona-the-Octocat-${{ steps.date.outputs.date }}

Outputs :

* Test with environment variables
nightly-tag-2020-03-31 - nightly-release-2020-03-31

* Test with input
Hello Mona-the-Octocat-2020-03-31