Returns the numeric day of the week where Sunday1 for the provided date in dateSecs or the current date, if one is not provided. The provided date is a string representing the number of seconds since 00:00:00 GMT, 1 January, 1970.

Returns the number of seconds since 00:00:00 GMT, 1 January, 1970 to the current time on the last day of the month in the date provided in dateSecs or the current date if one is not provided. The provided date is a string representing the number of seconds since 00:00:00 GMT, 1 January, ...

Determines how many days difference there is between 19700101 and the provided date.