The phrase "some two days" is grammatically correct and can be used in written English.
It is often used to indicate a vague or approximate amount of time. Example: I will be away for some two days on my business trip.
Further, Smith found that in the area of Nepal she studied, SODIS bottles had to be left for some two days to completely disinfect the water.
During his first appearance he made statements which he subsequently changed on a voluntary reappearance before the grand jury some two days before the indictment was returned.
American supermaxi Comanche performed the ultimate comeback to take line honours in the Sydney to Hobart yacht race, some two days after she turned back to the start line, damaged and ready to withdraw.
The speaker appeared unhappy with comments the mayor made in a news conference on Oct. 16, when Mr. Bloomberg insisted that he and his aides had "answered every single question, including some two days ago that his staff and the governor's staff has asked for, period, end of story".
There are some two days that I forgot to take.
But, even being so near, Proxima b would take us eighty thousand years (some thirty million days) to reach — a very long day's journey into day.
Records show that Stanley arrived in Paris some ten days later than he said he did.
The letter must have impressed Ms. Hughes; the rights were granted some five days later.
He subsequently passed out and bled to death; his body was discovered some four days later.
Malaysia Airlines flight MH370 is still missing, some five days after it vanished in the air near Vietnam.
The case captured national headlines after she was reported missing by her husband some nine days after last being seen.
