extract(dow from ...)’s day number- ing. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); time (start of current statement); see Section 9.9.4 timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day numbering. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); time (start of current statement); see Section 9.9.4 timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day number- ing. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); time (start of current statement); see Section 9.9.4 timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 211 Chapter 9. Functions and Operators Function

extract(dow from ...)’s day numbering. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); time (start of current statement); see Section 9.9.4 timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day numbering. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed 3 days 237 Chapter 9. Functions and Operators Function Return Type Description Example Result clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); time (start of current statement); see Section 9.9.4 timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day number- ing. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e. zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); Operators Function Return Type Description Example Result timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day number- ing. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e., zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); Operators Function Return Type Description Example Result timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)’s day numbering. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, i.e., zero hours and 36 hours output as 12, while HH24 outputs the full hour value, which can exceed interval Subtract from current_date (at midnight) age(timestamp ’1957-06-13’) 43 years 8 mons 3 days clock_timestamp() timestamp with time zone Current date and time (changes during statement execution); Operators Function Return Type Description Example Result timeofday() text Current date and time (like clock_timestamp, but as a text string); see Section 9.9.4 transaction_timestamp() timestamp with time

extract(dow from ...)'s day number- ing. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, for example zero hours and 36 hours both output as 12, while HH24 outputs the full hour value, which Subtract from current_date (at midnight) age(timestamp '1957-06-13') 43 years 8 mons 3 days clock_time- stamp() timestamp with time zone Current date and time (changes dur- ing statement ex- ecution); (start of cur- rent statement); see Section 9.9.4 timeofday() text Current date and time (like clock_time- stamp, but as a text string); see Section 9.9.4 transac- tion_time- stamp() timestamp with

extract(dow from ...)'s day numbering. • to_char(interval) formats HH and HH12 as shown on a 12-hour clock, for example zero hours and 36 hours both output as 12, while HH24 outputs the full hour value, which Subtract from current_date (at midnight) age(time- stamp '1957-06-13') 43 years 8 mons 3 days clock_time- stamp() timestamp with time zone Current date and time (changes dur- ing statement ex- ecution); date and time (like 236 Functions and Operators Function Return Type Description Example Result clock_time- stamp, but as a text string); see Section 9.9.4 transac- tion_time- stamp() timestamp with