In the sentence "Some university students carried out a campaign 【where】 they celebrated their whole day without cell phones", I understand "where..." is an attributive clause. Question is, is the sentence "some university students carried out a campaign 【that】 they celebrated their whole day without cell phones" correct? Can "that..." be seen as an appositive clause to explain "campaign"? Thanks in advance!!
Thanks for your opinion! Can you please explain in detail why the second one is wrong?