Glossary
Previous day high and low PDH · PDL
In short
The previous day high (PDH) and low (PDL) are the highest and lowest prices of the last completed trading day. They are among the most watched levels in intraday trading.
The same for week, month and quarter
The idea works on every higher timeframe: previous week high and low (PWH, PWL), month (PMH, PML) and quarter (PQH, PQL). The larger the timeframe, the more attention a level usually gets.
When does the day end?
On forex charts, the trading day often ends at 17:00 New York time, not at midnight. Which candle counts as the previous day therefore depends on the session settings of your chart or broker.