so just to double-check what you expect:

on Nov 15, when you click "Month" you expect roughly Oct 15 - Nov 15 rather than Nov 1 - Nov 15 (which is what's happening now)?  is that correct?

this is how week works (just the last 7 days), so we should probably be consistent.  we might want to double-check this isn't intentional, though.

It's more than that: In the old UI, the end date for the month view is always today.

When I switch to month view and click the left arrow to go back in time, I get:

Tuesday, November 1, 2016 to Today - Thursday, November 10, 2016
Saturday, October 1, 2016 to Today - Thursday, November 10, 2016
Thursday, September 1, 2016 to Today - Thursday, November 10, 2016

In effect, it's not grouping by "one month at a time", but "all history entries from n months ago until now"

Deleted: FwpYFM35dRz.png 69.5 KB

	FwpYFM35dRz.png 69.5 KB View Download

ah, yeah, ok

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2e33a4d2c2d2add03be4ddfcb9647781d947b516

commit 2e33a4d2c2d2add03be4ddfcb9647781d947b516
Author: calamity <calamity@chromium.org>
Date: Thu Nov 17 09:14:08 2016

Fix grouped history query range for months.

This CL fixes an issue where the end times for grouped history queries
were not being set and adds tests to prevent regressions.

BUG= 661882 

Review-Url: https://codereview.chromium.org/2464323004
Cr-Commit-Position: refs/heads/master@{#432824}

[modify] https://crrev.com/2e33a4d2c2d2add03be4ddfcb9647781d947b516/chrome/browser/ui/webui/browsing_history_handler.cc
[modify] https://crrev.com/2e33a4d2c2d2add03be4ddfcb9647781d947b516/chrome/browser/ui/webui/browsing_history_handler.h
[modify] https://crrev.com/2e33a4d2c2d2add03be4ddfcb9647781d947b516/chrome/browser/ui/webui/browsing_history_handler_unittest.cc