Baden on "[Plugin: T(-) Countdown] Default expiration and Custom fields"

Please read the documentation

Replace the counter:

[tminus t="+5 seconds"] <h1>Some BIG text</h1> [/tminus]

Replace text above the counter:

[tminus t="+5 seconds" launchtarget="above"] <h1>Some BIG text</h1> [/tminus]

Replace text below the counter:

[tminus t="+5 seconds" launchtarget="below"] <h1>Some BIG text</h1> [/tminus]