Since there is no equivalent of AM or PM in Hindi we have to mention the time of the day along with the specific clock time. For example if we have to say 3 AM, the Hindi equivalent will be रात के/में तीन बजे which literally means 3 o'clock of/in night.

English Hindi Transliteration Notes
Now अब/अभी ab/abhī
Later बाद में/फिर bāda mēṃ/phira
Before पहले pahalē
After बाद bāda
Dawn उषाकाल uṣākāla represents 01:00-03:59, rarely used (use rāt for 20:00-03:59)
Morning सुबह/सवेरा subaha/savērā savērā represents 04:00-05:59, subaha represents 06:00-10:59
Day दिन dina also represents 04:00-19:59, but cannot follow time words.
Noon दोपहर/मध्याह्न dopahara/madhyāhna madhyāhna is a tadbhava word, dopahara represents 11:00-16:59
Afternoon तिसरा पहर/अपराह्ण tisarā pahara/aparāhṇa aparāhṇa is a tadbhava word, tisarā pahara is rarely used currently, use dopahara instead
Twilight गोधूली godhūlī godhūlī=go(cattle)+dhūlī(dust). It basically represents the time when the home bound herds of cattle return making dust clouds with their hooves. Represents either savērā or śāma.
Evening शाम/संध्या śāma/saṃdhyā saṃdhyā is mostly used in literary contexts, śāma represents 17:00-19:59.
Night रात rāt represents 20:00-03:59

Clock timeEdit

English Hindi Transliteration
1 AM रात के एक बजे raat kē ēka bajē
7 AM सुबह के सात बजे subhē saath bajē
2 PM दोपहर के दो बजे dopahara kē do bajē
6 PM शाम के छै बजे śāma kē che bajē
7 PM शाम के सात बजे śāma kē sāta bajē
8 PM रात के आठ बजे rāta kē āṭha bajē
9 PM रात के नौ बजे rāta kē nau bajē
midnight आधी रात ādhī raat
Half past साढे sāḍhē
Half past 6 (6:30) साढे ६ (६:३०) sāḍhē 6
Quarter until पौने paunē
Quarter until 4 (3:45) पौने ४ (३:४५) paunē 4
Quarter past सवा savā
Quarter past 9 (9:15) सवा ९ (९:१५) savā 9
20 minutes past 8 (8:20) ८ बजकर २० मिनट (८:२०) 8 bajakara 20 minaṭa
12 minutes past 3 (3:12) ३ बजकर १२ मिनट (३:१२) 3 bajakara 12 minaṭa
7 minutes to 10 (9:53) १० बजने को ७ मिनट (९:५३) 10 bajanē ko 7 minaṭa

There are two exceptions to the Half past. Half past one (1:30) is डेढ (ḍēḍha) and half past 2 (2:30) is ढाई (ḍhāī). A fun way to remember their order would be 'Unless you dare (Lets say this represents डेढ) you die (and this represents ढाई). Voila!