In most situations it is enough to work with the local currency, but currency becomes an issue when you are trying to issue invoices to clients abroad. Now you can choose any currency you like when creating a new invoice:

Timebase will apply the coresponding currency exchange rate for any chosen date and today’s rate for future dates. You can also edit the invoice date after issuing and Timebase will adjust the exchange rate accordingly.

Even if you issue one invoice in USD, another one in GBP and a third in RUB, you can still sum their values in local currency based on the currency exchange rates.