* * * * 0 

you can use above cron job to run on every week on sunday, but in addition on what time you want to run this job for that you can follow below concept :

* * * * *  Command_to_execute
- � � � -
| | | | |
| | | | +�� Day of week (0�6) (Sunday=0) or Sun, Mon, Tue,...
| | | +���- Month (1�12) or Jan, Feb,...
| | +����-� Day of month (1�31)
| +������� Hour (0�23)
+��������- Minute (0�59)

crontab网站提供了实时结果显示:https://crontab.guru/#5_8_*_*_0

在指定cron值时，您需要确保您的值在该范围内。例如，一些cron使用0-7范围表示星期几，其中0和7表示星期日。我们没有(请看下面)。

Seconds: 0-59
Minutes: 0-59
Hours: 0-23
Day of Month: 1-31
Months: 0-11
Day of Week: 0-6

参考:https://github.com/ncb000gt/node-cron

* * * * 0 

you can use above cron job to run on every week on sunday, but in addition on what time you want to run this job for that you can follow below concept :

* * * * *  Command_to_execute
- � � � -
| | | | |
| | | | +�� Day of week (0�6) (Sunday=0) or Sun, Mon, Tue,...
| | | +���- Month (1�12) or Jan, Feb,...
| | +����-� Day of month (1�31)
| +������� Hour (0�23)
+��������- Minute (0�59)

10 * * *太阳

Position 1 for minutes, allowed values are 1-60
position 2 for hours, allowed values are 1-24
position 3 for day of month ,allowed values are 1-31
position 4 for month ,allowed values are 1-12 
position 5 for day of week ,allowed values are 1-7 or and the day starts at Monday. 

@每周工作对我更好! 例如，添加crontab -e，它将在每个周日0:00 AM工作 @weekly /root/fd/databasebackup/week.sh >> ~/test.txt