The Federal Ministry of Labor and Social Affairs (BMAS) has presented a draft bill for the revision of the Working Hours Act (ArbZG-E) which will detail the requirements of the Federal Labor Court (BAG) and the European Court of Justice (ECJ) for the already mandatory recording of working hours. For more information on these judgements, see the DGB press release regarding the "timeclock" judgement, here.
The draft creates an obligation for the employer to electronically record working hours. There are however possible exceptions which allow for non-electronic recording, for example by collective agreement, company or service agreement. Non-electronic time recording is also permitted during the first year of the law coming into force, so that companies can adapt accordingly. Depending on the size of the company, this transitional period is longer: companies with fewer than 250 employees have two years, and five years for fewer than 50 employees. Companies with fewer than ten employees as well as foreign employers without a permanent establishment in Germany can do without the electronic form altogether.
For more information, see the BMAS press release here.