Researchers have used time diary methods for analysing people's behaviour since the mid-1920s in many countries. During these early efforts, a spirit of co-operation developed among people performing time use research. While working for the United Nations Institute for Training and Research and the Hungarian Academy of Sciences in the 1960s, Alexander Szalai co-ordinated the first multinational time use study. This project developed a standardised sampling procedure, diary format, and data collection procedure implemented initially by twelve countries in 1965. Other countries later copied the Szalai approach, and many of the original twelve have since replicated their original 1965 studies. Professor Philip Stone, a collaborator in this project, has more recently deposited data from the Szalai studies at the Murray Centre at Radcliffe College. Co-operative efforts in the time use field between scholars from many countries led to the creation of the Working Group on Time Budgets and Social Activities during the International Sociological Association meeting in Varna, Bulgaria in 1970. This working group voted to transform itself into the International Association for Time Use Research (IATUR) during its 1988 meeting in Hungary. IATUR now maintains a web site of on-going activities in the time use field as well as co-ordinating time use conferences and research meetings. In 1985, with support from Statistics Canada, a specialised collection of time use related documents and machine readable bibliography was established at St Mary's University, under the direction of Andrew Harvey, with a clone collection in the Statistics Canada Library. That collection has continued to expand with the machine readable bibliography currently containing in excess of 5000 references, many abstracted. This spirit of cross-national and cross-institutional co-operation in the production of time use data as well as the development of many time use data and information archives inspired the development of the Multinational Time Use Study. In the late 1980s, Jonathan Gershuny and Sally Jones, then at the School of Social Sciences at the University of Bath, collected time use data sets performed in 20 countries after the original Szalai study, and prepared a version of these data sets which would allow cross-national comparability. The multinational file, which began as World 1 and has now progressed to World 5.5, has in the past limited the age range and the detail of demographic variables to allow for maximum comparability of the files. The upcoming versions building on this original base will include more variables and the complete age ranges collected in the various studies. The spirit of multi-national and multi-agency co-operation has continued through the present century. Eurostat has co-ordinated the development of Harmonised European Time Use Study (HETUS) data collection guidelines, which were piloted in 20 countries between 1996 and 1998, and have influenced time use data collection in 21 countries between 1999 and 2003. The United Nations has solicited international input into the harmonisation of time use study activity categories. From the summer of 1998, time use researchers from the University of Melbourne in Australia, the University of Essex in the UK, and two Canadian universities, St Mary's and The University of Calgary, have collaborated to expand and improve the Multinational Time Use Study. Team members at Calgary have rechecked the original syntax used to convert the original data into earlier versions of the MTUS. The Essex team has assembled a document of the technical details of time use studies, acquired recent documentation of time use studies and scanned older documentation for distribution, and constructed this web site. The Melbourne and St Mary's teams have joined the Essex team in designing and co-ordinating the project, as well as in acquiring new data sets for inclusion in the file. The next versions of the MTUS will include more countries, more demographic detail, sequence data, and more ancillary characteristics associated with activities in time. The MTUS team is also working with a larger team, including the UK Data Archie, Statistics Sweden and Statistics Finland, to develop prototype data tables, a customised time use table production web site, and a harmonised data file for the Harmonised European Time Use Study project.