Now:
Timestamp:
Time:
Get timestamp
PHP
time()
Java
(int) (System.currentTimeMillis() / 1000)
Swift
NSDate().timeIntervalSince1970
Object-C
[[NSDate date] timeIntervalSince1970]
JavaScript
Math.round(new Date() / 1000)
Ruby
Time.now.to_i
Shell
date +%s
Groovy
(new Date().time / 1000).intValue()
Lua
os.time()
.NET/C#
(DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000
Erlang
calendar:datetime_to_gregorian_seconds(calendar:universal_time())-719528*24*3600.
SQLite
SELECT strftime('%s', 'now')
MySQL
SELECT unix_timestamp(now())