If you don't want the charge to appear on the next statement, change the date to when you want the charge to appear. For example, if the charge is an annual membership fee that is due on November 1st, change the date to November 1st.
To enter a charge you forgot to include on a previous statement, use the current date. Otherwise, the charge won't appear on the next statement.
When you print statements, QuickBooks normally includes only those charges you entered after the date of the last statement up through today. Postdated charges won't appear unless you specifically change the date range of the statement to include them.