The answer of first question is you can NOT know the exact arrival time of China Post International Parcel. Actually not only China Post, Hong Kong Post, Singapore Post and any other countries’ postal service, all have same problem.
The reasons of such unpredictable-arrival problem are as following:
China Post international parcels actually go through a network called Global Postal Union. The members of this union are postal companies or post ministry of different countries and most of the countries in the world belong to this union.
So parcels from China will go through many of the union member countries before arriving destination. The destination country post company is responsible for the delivery.
The key point is : Once the parcel was given to customs or airline and it is on the way to next union member’s system, China Post will no longer control the parcel and not even know the exact status and location of the parcel until next union member country scan this parcel.
After China Post lost control of the parcel, in tracking result, the parcel status will seems to be freeze or stuck in such status as “sent to airline”, “Export Security Scan”, “Export Customs Scan” etc for quite long time (2 to 4 weeks in regular season, and 4 to 8 weeks in rush season) . Once next postal union member scanned the parcel again and send the data back to China Post through Global Postal Union computer system, China Post then update the parcel status with new information. If destination country does not scan the parcel, or does not send the scan result to GPU, the status will freeze forever. So if your parcel status freeze in STA,ESS,ECS status for a couple of weeks, it does not necessarily mean your parcel has any problem
There is only one exception, if your parcel has something in this list https://track-chinapost.com/?p=650, the parcel will be rejected by customs and airline. In this case, the status will also freeze and you should open dispute and claim refund from shipper.
Although we can not predict the exact arrival time, it does not mean that we can know nothing about the arrival time. Actually we can use previous shipping statistic data and user feedback to estimate the approx arrival time.
Check our arrival time statistic report, you can easily find the average arrival time, max arrival time and shortest arrival time of parcels to your country.
In rush season, arrival time might be double or triple of regular season.
There are also many factors to affected the arrival time including national events and festival, departure port traffic situation etc. You can check our forum https://track-chinapost.com/?page_id=242 for more information.