In the Archive Editor, PI Message Logs, etc., the user can enter a start time and an end time. Sometimes, you want to look at a time range in the past. Most people do not think in terms of start time and end time (16-Jan-17 00:00:00 to 16-Jan-01:00:00); they think of how much time after the start time they want to see (16-Jan-17 00:00:00 to +1h) or how much time before the end time they want to see (-1h from 16-Jan-17 01:00:00). Please allow entry of times relative to the start time or end time (but obviously not both at the same time).
Originally posted on UserVoice