Currently, the Global Contributions tool will only show 20 edits per wiki in both the "by wiki" and "by date" view types. This means that when one sorts by date, it's fairly likely that you will not actually be shown edits that happened on a date, if they are not within the user's 20 most recent on a wiki. As a result, the "by date" view gives an incomplete picture of "person's actual edits by date".
As an example, viewing global contribs for SGill (WMF), no edits are shown between 12 May and 8 June, despite a large number of edits the user made on Meta between those date (because those edits are not within the 20 most recent the user made to Meta). This leads to misleading and/or confusing global contrib search results.

Feature request - Suggested (alternative) options for resolving this, in order of preference:

• show all edits for each date in the most recent X days when searching by date. (but I'm guessing that that's too resource-intensive).
• in the "by date" view, limit the search to 20 edits per date rather than 20 edits per wiki overall, and give a link underneath each batch to the complete onwiki contributions page (so that users are reminded that not all edits are shown).
• Add a link at the bottom of each 20 results, to "show more results from this wiki".
• Move the line "Limited to 20 results per wiki." from the bottom of the page to the top and increase font size.