Employers are being urged to allow workers to follow the crucial final Ashes Test which starts at The Oval this morning.
The TUC said "sensible" companies had been flexible in the past when staff wanted to follow other major events. The CBI said many firms are likely to let staff keep up with scores, at least.
Organisations, however, have been warned that computer networks could be affected by staff keeping up with the scorecard or live commentary on the internet.
CBI figures show that employers believe about 14% of workplace absence is not due to a genuine illness.
TUC general secretary, Brendan Barber, said he hoped employers would make arrangements to "allow people to follow their sporting heroes over the next few days".
The cricket series has reached an exciting climax with England leading 2-1 and needing only a draw to beat Australia and win the Ashes for the first time in 18 years.