You will need to install a user script manager extension to install this script.
WaniKani Ultimate Timeline displays a schedule of your upcoming reviews.
X-axis: Time when reviews become available.
Y-axis: Number of reviews in a timeslot.
Range slider: Set the number of hours to display on the graph (up to 168 hours).
Hover over a graph bar to display a detail window, which shows details about the reviews in that timeslot.
Click on a graph bar to anchor the detail window, then hover over individual review items for individual item info.
Click or drag along the top of the X-axis to highlight a time range. The detail window will show details about all reviews in that time range.
Current level reviews are indicated by a white arrow below the timeslot, a white background behind the timeslot, and a yellow "Current Level" box in the detail window.
Burn reviews are indicated by a black arrow below the timeslot, a black background behind the timeslot, and a black "Burn Items" box in the detail window.
Graph updates occur automatically every 15 minutes, and the timescale slowly moves to the left. As time passes, your available reviews will accumulate in the left-most timeslot, which represents "now".
Forced refresh is like clearing your browser cache. It is usually only needed if you do reviews on a different device or computer. Normally, you only need to return to the WaniKani dashboard after doing reviews, and the timeline will fetch your updated schedule.