Feature request: modify layer's start/end times instead of replacing layer

[Derek Lamb]

Often I am looking at an event, and realize that the time frame I put in initially was too short, and I want some time before and/or afterwards for more context. As best as I have been able to figure, the current way to do that is to delete the existing layer and add a new layer with a broader time range. Thus the old data has to be downloaded all over again., plus the new data. Would it be possible to right click (or on Mac two-finger-click) and have the menu include "Modify Layer" or "Extend Time Range" or "Change Start/End Time" with the option to prepend or append data of the same type at the same cadence as the original?