How to insert in the "deadline" field (in the BP in adding a task) the last business day of the current month?

Question

1C-Bitrix

I am doing a business process in which I need to add a task with a deadline of the last business day of the current month.

Answer 1

Number of days in the month
=date('t', {=System:Date})
Current month and year
=date('d.y', {=System:Date})
Last day of the month (glued together from previous lines) [lastDay]

=date('t', {=System:Date}) & '.' & date('d.y', {=System:Date})

Checking for working hours

=if( isWorkDay({=Variable:lastDay}),  'Да',  'Нет')

If the day is working - leave it as it is, if not - minus one working day

=if(  isWorkDay({=Variable:lastDay}),  {=Variable:lastDay},  addworkdays({=Variable:lastDay}, -1)  )

Total:

Блок 1: Установка переменной lastDay
{=date('t', {=System:Date}) & '.' & date('d.y', {=System:Date}) }

Блок 2: Установка времени в задаче
{=if(  isWorkDay({=Variable:lastDay}),  {=Variable:lastDay},  addworkdays({=Variable:lastDay}, -1)  )}

It is possible without a variable, but here such a tin will be