That is what I would call good vendor etiquette.

Since only the date shows up on the individual items, any customer who puts an item in their cart and notes the sale end date will not be disappointed if the sale ends at 11:59.  On the other hand, if a sale ends at some arbitrary earlier time during the final day, then customers must search out this information which, honestly, I did not know was even an option.

What is the point of having a sale, if you leave your customers feeling tricked?

A hint to vendors - it takes several positive experiences to overcome one negative one.  Don't be tricky.  If you want to limit a sale, put in less items, use a lower percentage, or have it end earlier, but don't end your sale at some weird time of day.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.