Hi isis.. Not sure how to interpret your stats but should not be a weekend issue..
When listing an item, choose a handling time of 'one business day'. This means you will need to ship the item within one business day after receiving cleared payment. For example, if you specify 1-day handling time and a buyer pays for an item on Tuesday, you have until 11:59:59 PM Pacific Time on Wednesday to upload a tracking number. For an order paid for on Friday, Saturday or Sunday, a tracking number must be uploaded by 11:59:59 PM Pacific Time on Monday. Weekends and holidays will not be considered a 'business day.'