During the Soviet occupation and for a period after it, the country used the Soviet numbering: +7 012 area code until 1993;[4] the legacy numbering was used for the national area codes until it was replaced in 2001–2003;[5] the domestic prefix “8” was replaced with “0” in 2024 (and fully deactivated in 2025[1]), despite being planned since 2001.[3][6] The delay was due to legacy emergency numbers 01, 02 and 03, which were kept active until 1 April 2022.[
From wikipedia https://en.wikipedia.org/wiki/Telephone_numbers_in_Lithuania:
Going through my phonebook and replacing 8’s with zeroes was a mess.