Daily Forex Charts

If FOREX trading is suppose to 24hrs trading, why is there a daily chart?

A day is a 24 hour period, whether trading stops or not. There have been hourly charts and 1-minute charts for years. Whatever period a trader finds useful.

Forex needs a cutoff each day for accounting and interest adjustments. This means 5PM New York time because 5PM is the end of the banks and New York is the last currency trading center to be open. The day starts at the international date line and the first banking center is Sidney, then the Asian banks and then European banks open.