By End a letter, Past tenses

Hi, Can a past tense work, as well as the one used, the present perfect, here -- when we have a phrase 'for the last three weeks' or a similiar one thereof? I have written my friend a letter every other day for the last three weeks. I wrote my friend a letter every other day for the...

Hi, Can a past tense work, as well as the one used, the present perfect, here -- when we have a phrase 'for the last three weeks' or a similiar one thereof? I have written my friend a letter every other day for the last three weeks.