bmpurge file -before [timestamp, string] -after [timestamp, string]
Before: all bookmarks before this date will be erased
After: all bookmarks after this date will be erased
File: Path to the bookmarks HTML file.
File will be overwritten without warning. Always keep a backup.
bmpurge path/to/file -before "01 Jan 2018 12:00" will erase all bookmarks created before 01 Jan 2018, 12:00.
bmpurge path/to/file -after "01 Jan 2018 12:00" will erase all bookmarks created after 01 Jan 2018, 12:00.
bmpurge path/to/file -before "31 June 2018 22:00" -after "01 Jan 2018 12:00" will erase all bookmarks created between 01 Jan 2018, 12:00 and 31 June 2018, 22:00.
bmpurge path/to/file -before "01 Jan 2018 12:00" -after "31 June 2018 22:00" will erase all bookmarks except ones created between 01 Jan 2018, 12:00 and 31 June 2018, 22:00.