Date to Day ->Parse Error at char(0): Formula: tried to apply numeric operator to string v

[Sammie]

Hi

Tried to create a column from date to day of the week, the formula should works fine DateTimeformat(DateTimeParse([Date],'%Y/%m/%d'),'%A'); however i'm getting error as below:

Formula (28) Parse Error at char(0): Formula: tried to apply numeric operator to string value (Expression #2)

I've read somewhere could be because previous data is string. The date is extract out using Regex and then convert using DateTime tool. 

Can you please help? 

[Sammie]

First part was my error!

Thanks for the conditional formula also.