英语翻译1.payment is to be made by irrevocable L∕C at 60 days si

英语翻译
1.payment is to be made by irrevocable L∕C at 60 days sight to be opened 5 to 20 days prior to the date of delivery.2.i wonder whether you would consider 90 day‘s L|C as i suggest i sincerely hope you are able to make a last minute change on this aspect.