Find the day of the week for a date field via formula #inSalesforce

If the field is theDateField__c and the field which will calculate the day of the week for the mentioned date in theDateField__c is suppose named DayoftheWeek__c :

Formula field named DayoftheWeek__c with return type TEXT :

CASE(

MOD(theDateField__c - DATE(1900, 1, 1), 7),

0, "Monday",

1, "Tuesday",

1, "Wednesday",

1, "Thursday",

1, "Friday",

1, "Saturday",

1, "Sunday",

""

)