For a Good Strftime

• Sun
• Sunday
• Dec
• December
• 9
• 7
• 12
• 26
• PM
• 47
• 0
• 18
• 2018
• +0000
• UTC

Seconds

• %S - Second of the minute (00..60)
• %L - Millisecond of the second (000..999)
• %s - Number of seconds since 1970-01-01 00:00:00 UTC.

Minutes

• %M - Minute of the hour (00..59)

Hours

• %H - Hour of the day, 24-hour clock (00..23)
• %I - Hour of the day, 12-hour clock (01..12)
• %k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
• %l - Hour of the day, 12-hour clock, blank-padded ( 0..12)

Days

• %a - Abbreviated weekday name (“Sun”)
• %A - Full weekday name (Sunday)
• %w - Day of the week (Sunday is 0, 0..6)
• %u - Day of the week (Monday is 1, 1..7)
• %d - Day of the month (01..31)
• %e - Day of the month (1..31)
• %j - Day of the year (001..366)

Weeks

• %w - Day of the week (Sunday is 0, 0..6)
• %U - Week number of the current year, starting with the first Sunday as the first day of the first week (00..53)
• %V - Week number of year according to ISO 8601 (01..53)

Months

• %b - Abbreviated month name (Jan)
• %B - Full month name (January)
• %m - Month of the year (01..12)

Years

• %y - Year without a century (00..99)
• %Y - Year with century

Others

• %p - Meridian indicator (AM or PM)
• %P - Meridian indicator (“am” or “pm”)
• %c - Preferred local date and time representation
• %Z - Time zone name
• %% - Literal % character
• %C - Century (20 in 2009)
• %D - U.S. Date (%m/%d/%y)
• %n - Newline (n)
• %t - Tab character (t)