Houkago Chronoswitch

In 2026, Takada and Yunomi are idly wasting their time at a prestigious all-girls middle and high school. One day, they pick up a mysterious kitchen timer... and when they open their eyes, they find themselves in the year 2006! An adventure that takes place in an all-girls school and involves time travel, directly connecting them to the future!!

(Source: Akita Shoten, translated)