The head office (Chernobyl) working hours are 9.30 a.m.-6.00 p.m. (GMT+2, Kiev) Monday - Friday. Kyiv's current time is ....
For your convenience - answers to the most frequently asked questions are here.
You can book scheduled group tour as long as the date in the tour calendar is available, but not later than 4 days before the tour.
To book a private tour for the date that is convenient to you possible no later than 1 week before the desired date of the tour.