boogiman> Такой формат привычен пользователям
Она легко переводится в тип datetime

datetime dat_
dat_ = datetime(date(em_1.text))
dw_1.retrieve(dat_)
Вообще категорически не рекомендуется так делать. Для получения значения EditMask control есть специальная функция.
PB HelpGetData PowerScript function:
Syntax 2 For EditMask controls

Description

Gets the unformatted text from an EditMask control.

Controls

EditMask controls

Syntax

editmaskname.GetData ( datavariable )

Argument Description
editmaskname The name of the EditMask control containing the data.
datavariable A variable to which GetData will assign the unformatted data in the EditMask control. The datatype of datavariable must match the datatype of the EditMask control, which you select in the Window painter. Available datatypes are date, DateTime, decimal, double, string, and time.

Return value

Integer. Returns 1 if it succeeds and -1 if an error occurs. If any argument's value is null, GetData returns null.

Usage

You can find out the datatype of an EditMask control by looking at its MaskDataType property, which holds a value of the MaskDataType enumerated datatype.