My team does the same thing... every single month for every single client. 

Think of it like this... 

Parent Task

>> First thing we have to do

>> Second thing we do 3 days later

>> Last thing we do 5 days after the second thing

Every. Single. Month. 

There is absolutely NO way to automate this is any way in Zoho Projects. 

Task Templates? Don't exist. 

Recurring task? The sub-task dependencies get lost when it recurs

As far as I can tell, there is no way to automate regular work in Zoho Projects... and it's really frustrating.