One of the most important tasks facing a digital school teacher is to prepare a school leaver who is able to use the acquired knowledge in further life and generate new ideas, offer non-standard solutions, go beyond the usual patterns and circumstances. The authors investigate the problem of substantiating the effectiveness of using timeline services for the development of schoolchildren's creative thinking in additional education. The purpose of the study is to research the didactic potential of interactive timelines in the additional education classroom for the development of schoolchildren's creative thinking. The methodology is based on identifying the possibilities of additional education and technologies of the university's digital environment for the formation of creative thinking components; on clarifying the study program and methods of organizing activities in studios when creating time lines. The experimental work was carried out in studios for speech development, photo and video art. The Timeline JS service is used to create timelines. The results show the study program, methods of organizing activities in studios when creating timelines: displaying facts in chronological order, compiling algorithms, creating biographies, and presenting statistics. Difficulties that complicate the use of services are also formulated: management of temporary resources, the need to develop criteria and indicators of the effective use of web applications of corresponding designation. The results obtained can be used in additional education classes for career guidance, free time organization and support of schoolchildren's intellectual development.