Maintenance of the Singaporean server aka the South East Asian server was previously set to begin today but a major public outcry on Reddit has prompted Valve to push back the downtime.
The complaints are mostly originating from the longer than usual downtime and also it coinciding with a public holiday (Thaipusam) in Malaysia and Singapore. While the date has been pushed back to the 21st of January, the maintenance will still last a whopping 48 hours.
Australian server will be down today.
Source: Dota 2