Hi @cjl , and welcome to the Streamlit community!
Have you tried with:
import time
for seconds in range(60):
with placeholder.container():
kpi1, kpi2 = st.columns(2)
kpi1.write(f"Hourglass with flowing sand {seconds} seconds have passed")
kpi2.write(f"Hourglass with flowing sand {seconds * 2} seconds have passed")
time.sleep(1)
placeholder.empty()