The phrase "across two days" is correct and usable in written English.
It can be used to indicate that something occurs or is spread over a duration of two days.
Example: "The event will take place across two days, starting on Saturday and ending on Sunday."
Alternatives: "over the course of two days" or "during a span of two days."
The day after the final acclimation, rats underwent four 30 min sessions of conditioning across two days which involved each rat being exposed to both chambers on each day with a four hour period between each conditioning session within a day, and a reversed order of chamber exposure on the second day.
Across two days, she was interviewed by the entire partnership.
Senators told their own personal campaign stories across two days of debate on the issue and their experience in many cases dictated how they voted.
It also pales in comparison to the roughly 26 million viewers averaged by the inaugural "Idol Gives Back" special last year, when it was spread across two days.
The event – also featuring Lana Del Rey and Jack White – is expected to be attended by 100,000 people across two days in June.
A friend and I did a similar thing at NOS Primavera Sound this year (we counted "seven to 12" black people, including myself, across two days).
Who hasn't dreamed of doing that?" Every major league team routinely holds tryout camps, but this one is unusual because it focuses on different boroughs each day and extends across six days.
These staff cannot and should not be stretched across seven days.
In April, the Los Angeles Philharmonic hosted the Reykjavík Festival, which sprawled across eight days of programming.
It can't be the jury, which had four black members and conscientiously deliberated for 14 hours across three days.
Held across three days, Ideas City presented some 100 events, including conferences, performances, activities and a street fair.
