* * * * 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)

以人类可读的方式使用crontab构建器的Cron作业表达式

下面是对crontab格式的解释。

# 1. Entry: Minute when the process will be started [0-60]
# 2. Entry: Hour when the process will be started [0-23]
# 3. Entry: Day of the month when the process will be started [1-28/29/30/31]
# 4. Entry: Month of the year when the process will be started [1-12]
# 5. Entry: Weekday when the process will be started [0-6] [0 is Sunday]
#
# all x min = */x

所以根据这个，你的5 8 * * 0会在每周日8:05运行。

下面是crontab文件的格式。

{分钟}{小时}{月日}{月日}{用户}{path-to-shell-script}

因此，在每个周日的午夜运行(周日通常是0，在一些罕见的情况下是7):

0 0 * * 0 root /path_to_command

@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

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